test: run unused and gosimple over all packages at once
test: run unused and gosimple over all packages at once

fmt pass went from ~20 CPU minutes to ~1 CPU minute.

Fixes #7377

etcd-io/etcd,glevand/coreos--etcd,CrazyJvm/etcd,dannysauer/etcd,etcd-io/etcd,visheshnp/etcd,ajityagaty/etcd,bdarnell/etcd,YuleiXiao/etcd,akauppi/etcd,sebrandon1/etcd,heyitsanthony/etcd,a-robinson/etcd,joshix/etcd,bluebreezecf/etcd,mqliang/etcd,sinsharat/etcd,akauppi/etcd,jlamillan/etcd,handsomesun/etcd,tguangch/etcd,armstrongli/etcd,sebrandon1/etcd,whuwxl/etcd,ajityagaty/etcd,dannysauer/etcd,lumjjb/etcd,whuwxl/etcd,heyitsanthony/etcd,coreos/etcd,fanminshi/etcd,handsomesun/etcd,mkumatag/etcd,mqliang/etcd,lumjjb/etcd,gyuho/etcd,a-robinson/etcd,plasticbox/etcd,YuleiXiao/etcd,cockroachdb/etcd,armstrongli/etcd,yudai/etcd,bdarnell/etcd,ajityagaty/etcd,rnaveiras/etcd,coreos/etcd,mickep76/etcd,mkumatag/etcd,jlamillan/etcd,sinsharat/etcd,li-ang/etcd,yudai/etcd,joshix/etcd,xiang90/etcd,bluebreezecf/etcd,gyuho/etcd,vimalk78/etcd,li-ang/etcd,vimalk78/etcd,plasticbox/etcd,fanminshi/etcd,lorneli/etcd,mickep76/etcd,xiang90/etcd,tguangch/etcd,mkumatag/etcd,visheshnp/etcd,glevand/coreos--etcd,cockroachdb/etcd,CrazyJvm/etcd,rnaveiras/etcd,mqliang/etcd,etcd-io/etcd,rnaveiras/etcd,lorneli/etcd