Update devcontainer

[maresb]

What is this PR about?

Brushes the dust off of the Gitpod dev container:

• Rebuild it regularly (weekly, plus after each release)
• Base it on the latest tag of the upstream Micromamba dev container
• Remove a flaky hack which attempted to cache the pre-commit extensions
• Add the Jupyter extension in the container

Checklist

• Explain important implementation details 👆
• Make sure that the pre-commit linting/style checks pass.
• Link relevant issues (preferably in nice commit messages)
• Are the changes covered by tests and docstrings?
• Fill out the short summary sections 👇

Major / Breaking Changes

• ...

New features

• ...

Bugfixes

• ...

Documentation

• ...

Maintenance

• Update the dev container

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📚 Documentation preview 📚: https://pymc--7017.org.readthedocs.build/en/7017/

[maresb]

I just tested it, and it appears to be working sensibly.

[twiecki]

Thanks!