Split pinned and unpinned base image pipelines.

[williamblevins]

Change Description

Breakdown the base-images pipeline in pinned and unpinned to improve image registry structures and isolation.

Change Type

Select ONE:

• [ ] Documentation

• [ ] Stability bug fix

• [X] Other

• [ ] Other - special case

Testing Changes

Select ANY that apply:

• [ ] New Tests

• [ ] Existing Tests

• [ ] Test Framework

• [X] CI System

• [ ] Other

Consensus Changes

• [ ] Consensus Changes

API Changes

• [ ] API Changes

Documentation Additions

• [ ] Documentation Additions

[williamblevins]

Can any of these images be removed (IE. not supported)?

[linhuang-blockone]

I think at least centos can be removed. Keep Ubuntu 18.04, 20.04, one Amazon Linux, and at least one MacOS. We can remove anything else we decide in the future.