ci-linux: Remove unmaintained local-conda runs

[mkoeppe]

📚 Description

These are jobs that run directly on the GH Actions container instead of using Docker.
We remove them.

These jobs have been failing for a long time.
Newer tests for conda-forge have been added in ci-conda.yml, which makes these ones here obsolete.

📝 Checklist

• I have made sure that the title is self-explanatory and the description concisely explains the PR.
• I have linked an issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation accordingly.

⌛ Dependencies

[tobiasdiez]

Shouldn't be then the corresponding part of the tox ini file also be removed? Also, what is the difference between this tox-based conda run and the one in conda-ci?

[mkoeppe]

Shouldn't be then the corresponding part of the tox ini file also be removed?

No, the tox.ini can be used locally.

[mkoeppe]

what is the difference between this tox-based conda run and the one in conda-ci?

The one removed here builds sage-the-distribution on top of conda-forge. But this mode of installation is also tested using docker-conda-forge, which is more robust because we have more control over this environment than we do over the github actions container.

In contrast, in conda-ci, we use the "experimental" method of running sagelib directly on top of conda-forge.

[tobiasdiez]

Thanks for the explanation. Makes sense!

[mkoeppe]

Thank you!

[github-actions]

Documentation preview for this PR is ready! 🎉
Built with commit: e25deb6

[dimpase]

merging, as it improves CI by removing broken tests