Remove gem_available?
Remove gem_available?

This isn't used anywhere in the codebase, doesn't have any tests, and
isn't a good idea to use even if you wanted to.

Fixes #5920

jimblesm/spree,robodisco/spree,piousbox/spree,agient/agientstorefront,tesserakt/clean_spree,JDutil/spree,camelmasa/spree,jasonfb/spree,rajeevriitm/spree,raow/spree,caiqinghua/spree,CiscoCloud/spree,moneyspyder/spree,AgilTec/spree,jspizziri/spree,yiqing95/spree,kewaunited/spree,madetech/spree,patdec/spree,keatonrow/spree,Machpowersystems/spree_mach,zaeznet/spree,quentinuys/spree,calvinl/spree,nooysters/spree,jaspreet21anand/spree,SadTreeFriends/spree,archSeer/spree,pervino/spree,welitonfreitas/spree,Ropeney/spree,locomotivapro/spree,edgward/spree,orenf/spree,reinaris/spree,thogg4/spree,jasonfb/spree,robodisco/spree,DarkoP/spree,reidblomquist/spree,njerrywerry/spree,groundctrl/spree,jeffboulet/spree,welitonfreitas/spree,archSeer/spree,progsri/spree,mindvolt/spree,adaddeo/spree,imella/spree,dandanwei/spree,Hawaiideveloper/shoppingcart,KMikhaylovCTG/spree,APohio/spree,rajeevriitm/spree,ahmetabdi/spree,pervino/spree,delphsoft/spree-store-ballchair,lyzxsc/spree,Engeltj/spree,ahmetabdi/spree,azclick/spree,agient/agientstorefront,gregoryrikson/spree-sample,caiqinghua/spree,lsirivong/spree,gautamsawhney/spree,SadTreeFriends/spree,mleglise/spree,thogg4/spree,shaywood2/spree,vcavallo/spree,cutefrank/spree,assembledbrands/spree,karlitxo/spree,tomash/spree,reinaris/spree,yiqing95/spree,softr8/spree,dafontaine/spree,Ropeney/spree,vinayvinsol/spree,groundctrl/spree,robodisco/spree,ayb/spree,DarkoP/spree,hifly/spree,alvinjean/spree,JDutil/spree,gautamsawhney/spree,abhishekjain16/spree,jimblesm/spree,kewaunited/spree,gautamsawhney/spree,jparr/spree,carlesjove/spree,shekibobo/spree,trigrass2/spree,Boomkat/spree,fahidnasir/spree,useiichi/spree,carlesjove/spree,fahidnasir/spree,patdec/spree,madetech/spree,zaeznet/spree,maybii/spree,jaspreet21anand/spree,vinayvinsol/spree,brchristian/spree,omarsar/spree,FadliKun/spree,mleglise/spree,nooysters/spree,jeffboulet/spree,sideci-sample/sideci-sample-spree,agient/agientstorefront,sunny2601/spree,zamiang/spree,softr8/spree,useiichi/spree,vinsol/spree,locomotivapro/spree,hifly/spree,wolfieorama/spree,joanblake/spree,vcavallo/spree,builtbybuffalo/spree,CiscoCloud/spree,calvinl/spree,SadTreeFriends/spree,vcavallo/spree,moneyspyder/spree,azclick/spree,delphsoft/spree-store-ballchair,adaddeo/spree,rbngzlv/spree,caiqinghua/spree,azranel/spree,rakibulislam/spree,zamiang/spree,carlesjove/spree,wolfieorama/spree,caiqinghua/spree,quentinuys/spree,builtbybuffalo/spree,zaeznet/spree,NerdsvilleCEO/spree,alvinjean/spree,zaeznet/spree,maybii/spree,DynamoMTL/spree,NerdsvilleCEO/spree,kewaunited/spree,jparr/spree,sunny2601/spree,radarseesradar/spree,tomash/spree,vinsol/spree,pervino/spree,nooysters/spree,CiscoCloud/spree,beni55/spree,Hawaiideveloper/shoppingcart,madetech/spree,reidblomquist/spree,welitonfreitas/spree,rbngzlv/spree,Kagetsuki/spree,tesserakt/clean_spree,priyank-gupta/spree,KMikhaylovCTG/spree,sliaquat/spree,camelmasa/spree,rajeevriitm/spree,brchristian/spree,firman/spree,Kagetsuki/spree,dafontaine/spree,njerrywerry/spree,siddharth28/spree,pulkit21/spree,firman/spree,camelmasa/spree,Engeltj/spree,carlesjove/spree,locomotivapro/spree,njerrywerry/spree,lsirivong/spree,TrialGuides/spree,grzlus/spree,sfcgeorge/spree,edgward/spree,JDutil/spree,mindvolt/spree,azclick/spree,tancnle/spree,beni55/spree,delphsoft/spree-store-ballchair,vmatekole/spree,alvinjean/spree,camelmasa/spree,JuandGirald/spree,sunny2601/spree,yiqing95/spree,Engeltj/spree,Hawaiideveloper/shoppingcart,edgward/spree,dandanwei/spree,AgilTec/spree,archSeer/spree,keatonrow/spree,vulk/spree,quentinuys/spree,gregoryrikson/spree-sample,volpejoaquin/spree,jeffboulet/spree,zamiang/spree,hifly/spree,CiscoCloud/spree,APohio/spree,jspizziri/spree,orenf/spree,TimurTarasenko/spree,shekibobo/spree,hoanghiep90/spree,Ropeney/spree,azranel/spree,volpejoaquin/spree,NerdsvilleCEO/spree,rajeevriitm/spree,groundctrl/spree,reinaris/spree,tancnle/spree,APohio/spree,sunny2601/spree,dafontaine/spree,brchristian/spree,jaspreet21anand/spree,KMikhaylovCTG/spree,thogg4/spree,ramkumar-kr/spree,assembledbrands/spree,jimblesm/spree,derekluo/spree,mindvolt/spree,sideci-sample/sideci-sample-spree,dandanwei/spree,abhishekjain16/spree,TrialGuides/spree,softr8/spree,joanblake/spree,orenf/spree,raow/spree,DarkoP/spree,CJMrozek/spree,keatonrow/spree,FadliKun/spree,cutefrank/spree,sfcgeorge/spree,firman/spree,piousbox/spree,Kagetsuki/spree,beni55/spree,rakibulislam/spree,omarsar/spree,cutefrank/spree,azclick/spree,lyzxsc/spree,yushine/spree,fahidnasir/spree,vinsol/spree,hoanghiep90/spree,rakibulislam/spree,odk211/spree,shekibobo/spree,berkes/spree,vulk/spree,builtbybuffalo/spree,groundctrl/spree,jasonfb/spree,sfcgeorge/spree,moneyspyder/spree,delphsoft/spree-store-ballchair,jimblesm/spree,joanblake/spree,berkes/spree,dafontaine/spree,gregoryrikson/spree-sample,archSeer/spree,odk211/spree,gautamsawhney/spree,karlitxo/spree,keatonrow/spree,miyazawatomoka/spree,abhishekjain16/spree,alejandromangione/spree,Engeltj/spree,imella/spree,vmatekole/spree,vulk/spree,jspizziri/spree,radarseesradar/spree,shekibobo/spree,lsirivong/spree,adaddeo/spree,Lostmyname/spree,volpejoaquin/spree,zamiang/spree,karlitxo/spree,priyank-gupta/spree,vmatekole/spree,tesserakt/clean_spree,reidblomquist/spree,karlitxo/spree,Boomkat/spree,mindvolt/spree,firman/spree,Ropeney/spree,jspizziri/spree,FadliKun/spree,tancnle/spree,yushine/spree,jeffboulet/spree,alejandromangione/spree,ayb/spree,rbngzlv/spree,progsri/spree,yiqing95/spree,trigrass2/spree,raow/spree,rbngzlv/spree,Lostmyname/spree,lyzxsc/spree,mleglise/spree,JuandGirald/spree,vmatekole/spree,sideci-sample/sideci-sample-spree,ramkumar-kr/spree,shaywood2/spree,lyzxsc/spree,omarsar/spree,DynamoMTL/spree,orenf/spree,Hawaiideveloper/shoppingcart,kewaunited/spree,maybii/spree,assembledbrands/spree,hoanghiep90/spree,builtbybuffalo/spree,vinayvinsol/spree,azranel/spree,NerdsvilleCEO/spree,priyank-gupta/spree,maybii/spree,nooysters/spree,Lostmyname/spree,derekluo/spree,rakibulislam/spree,derekluo/spree,vulk/spree,imella/spree,Kagetsuki/spree,sliaquat/spree,fahidnasir/spree,wolfieorama/spree,grzlus/spree,progsri/spree,yushine/spree,azranel/spree,trigrass2/spree,JuandGirald/spree,shaywood2/spree,alejandromangione/spree,reinaris/spree,TimurTarasenko/spree,miyazawatomoka/spree,TrialGuides/spree,berkes/spree,AgilTec/spree,tomash/spree,alejandromangione/spree,grzlus/spree,ramkumar-kr/spree,edgward/spree,jparr/spree,ramkumar-kr/spree,quentinuys/spree,ayb/spree,tesserakt/clean_spree,trigrass2/spree,brchristian/spree,ahmetabdi/spree,adaddeo/spree,DarkoP/spree,Machpowersystems/spree_mach,pulkit21/spree,odk211/spree,patdec/spree,radarseesradar/spree,DynamoMTL/spree,JuandGirald/spree,locomotivapro/spree,KMikhaylovCTG/spree,Boomkat/spree,pervino/spree,agient/agientstorefront,patdec/spree,sliaquat/spree,tomash/spree,moneyspyder/spree,priyank-gupta/spree,joanblake/spree,useiichi/spree,ahmetabdi/spree,TimurTarasenko/spree,robodisco/spree,pulkit21/spree,calvinl/spree,omarsar/spree,dandanwei/spree,vinayvinsol/spree,siddharth28/spree,beni55/spree,useiichi/spree,hoanghiep90/spree,CJMrozek/spree,abhishekjain16/spree,Boomkat/spree,wolfieorama/spree,welitonfreitas/spree,odk211/spree,tancnle/spree,thogg4/spree,sliaquat/spree,CJMrozek/spree,cutefrank/spree,SadTreeFriends/spree,sfcgeorge/spree,jparr/spree,gregoryrikson/spree-sample,siddharth28/spree,AgilTec/spree,APohio/spree,pulkit21/spree,berkes/spree,lsirivong/spree,miyazawatomoka/spree,volpejoaquin/spree,Machpowersystems/spree_mach,TimurTarasenko/spree,alvinjean/spree,TrialGuides/spree,mleglise/spree,CJMrozek/spree,raow/spree,derekluo/spree,vcavallo/spree,madetech/spree,hifly/spree,yushine/spree,radarseesradar/spree,vinsol/spree,njerrywerry/spree,grzlus/spree,DynamoMTL/spree,ayb/spree,shaywood2/spree,jasonfb/spree,piousbox/spree,JDutil/spree,Lostmyname/spree,siddharth28/spree,FadliKun/spree,miyazawatomoka/spree,progsri/spree,jaspreet21anand/spree,softr8/spree,piousbox/spree,reidblomquist/spree,calvinl/spree