Fix failing builds
Drop easy-install in favour of directly installing pip Move rpi9 git into a builder image as we were running up against the 2hr build limit
Previous errors being seen here: https://gitlab.com/gitlab-org/gitlab-omnibus-builder/-/jobs/391080385
Fix needed so we can merge !128 (merged)
Changes pulled from @dustinmm80 WIP rpi10 MR here: !127 (merged)
Edited by DJ Mountney