Run docker image validation earlier
Run docker image validation earlier

It was possible for it not to get run if arm builds failed
and people might merge something broken given that arm
builds fail sometimes.

A more general clean up of circleci ordering is needed but this
is good for now. That more general clean up will be coming
when the release process is changed.

sgebbie/ponyc,dipinhora/ponyc,ponylang/ponyc,cquinn/ponyc,cquinn/ponyc,jemc/ponyc,sgebbie/ponyc,kulibali/ponyc,ponylang/ponyc,jemc/ponyc,sgebbie/ponyc,kulibali/ponyc,ponylang/ponyc,kulibali/ponyc,cquinn/ponyc,cquinn/ponyc,sgebbie/ponyc,kulibali/ponyc,jemc/ponyc,sgebbie/ponyc,dipinhora/ponyc,dipinhora/ponyc