Reversion back to Foxy has broken environment installation for Black and PyTest CI Jobs

[Purg]

See relevant pipelines here and here.

Looks like ubuntu-latest is being used as the OS host, the job is executing directly on the OS host, and the the actions/setup-python@v4 action is translating to trying to install the stated python version via a package manager, for which that version is not available to that OS version.

We should probably shift these actions to use docker and pull the appropriate python:3.8.10 versioned docker image.