Add black to linting requirements

[philnewm]

📜 Checklist

• Commits are cleanly separated with meaningful messages (simple features and bug fixes should be squashed to one commit)
• A changelog entry or entries has been added for any significant changes
• Follows the Pulp policy on AI Usage
• (For new features) - User documentation and test coverage has been added

See: Pull Request Walkthrough

Fixes pulp/pulp_deb#1471
PR created here due to this note
Let me know if this should be fixed in any other way.

[pedro-psb]

We've switched to using ruff instead of black.
The right move here is updating the oci_env lint runner: https://github.com/pulp/oci_env/blob/main/base/container_scripts/run_lint_tests.sh

You may also run it on the host, of course.
There is a Makefile that encapsulates various checks, as run in CI. It ended up in the pulp_rpm, but I just realized it's not being "distributed" by the plugin template updates (so pulp_deb doesn't have it). Now I'm curious why.

[philnewm]

Got it - thanks for the hint.
Makes way more sense to me now.

Will test the change to ruff locally later on.