Remove use of ci-docker-bases

[ddurst]

We want to retire ci-docker-bases. In order to do so, all projects using it must migrate their use to something else. It seems that buildhub2 is one of those projects.

Progress and notes can be found in the decision brief.

[jwhitlock]

🕘 We plan to stop updates to mozilla/cidockerbases:docker-latest image on October 1, 2022, less than 3 months away. This project uses this image in CircleCI. See mozilla/ci-docker-bases#322 for examples of projects that have successfully migrated away from mozilla/cidockerbases:docker-latest.

[jwhitlock]

🕘 We plan to stop updates to mozilla/cidockerbases:docker-latest image on October 1, 2022, less than 30 daysaway. This project uses this image in CircleCI. See mozilla/ci-docker-bases#322 for examples of projects that have successfully migrated away from mozilla/cidockerbases:docker-latest.

[jwhitlock]

We've now stopped updates to mozilla/cidockerbases:docker-latest.