Remove deprecated ical package (missing either-5 support)
Remove deprecated ical package (missing either-5 support)

CC @chrisdone

massysett/stackage,lwm/stackage,stackbuilders/stackage,k0ral/stackage,Daniel-Diaz/stackage,soenkehahn/stackage,ethercrow/stackage,fpco/stackage,wereHamster/stackage,mrkkrp/stackage,iand675/stackage,michalkonecny/stackage,fimad/stackage,athanclark/stackage,mstksg/stackage,mgajda/stackage,spencerjanssen/stackage,clinty/stackage,Shimuuar/stackage,int-index/stackage,peti/stackage,asr/stackage,garetxe/stackage,phaazon/stackage,creichert/stackage,jonschoning/stackage,simonmichael/stackage