Fix Sphinx configuration post-update

[snejus]

Adjust Sphinx configuration and release script

Changes:

• Update source_suffix in docs/conf.py to use dict format as required by newer Sphinx
  versions
• Fix typo in theme config: pygment_light_style -> pygments_light_style
• Improve release script to handle Sphinx intersphinx output formatting:
  • Replace tabs with spaces for consistent parsing
  • Add reference to sphinx.ext.intersphinx command in docstring
  • Update line parsing to match space-indented format
• Restructure CI workflow to ensure relevant dependencies are installed and changelog formatting is tested.

These changes ensure compatibility with newer Sphinx versions and improve the robustness
of the release script's reference parsing.

Edit:

While working on this PR GitHub decided to upgrade their linux/ubuntu runners with Ubuntu 24.04. Ubuntu upgrades are the worst: imagine not updating your system for 3 years and then suddenly upgrading everything to the most recent versions. At which point you start realizing that the final S in their LTS means Suffering instead of Support.

We use just a few system dependencies in our builds and as expected, things broke:

• libcairo2-dev now needs to be installed for pygobject.
• pandoc rst -> markdown conversion output has changed
• Completion tests are unhappy about bash / bash-completion upgrade, and I could not figure out why so I'm just xfailing that test in CI.

[github-actions]

Thank you for the PR! The changelog has not been updated, so here is a friendly reminder to check if you need to add an entry.

[JOJ0]

I looked through it and most LGTM as you can read in inline comments. I'm wondering how I could simulate a release in my fork and see what the final outcome is. Is it as easy as pushing a tag to the fork and then do whatever is to do the trigger the workflow (need to read docs how to do the latter)

Fun fact: I copied the output of "releasy.py changelog" to a github release and the preview showed actual bug emojies for :bug: - a feature not a bug! sweet! 🍭 (and now realize that this is in place since a couple of releases already haha ;-))

Anyway I think this is already good to go and let's kick out more releases soon for the real test.

[JOJ0]

I invested quite some time already trying to fix/understand the bash-completion issue. I suggest we keep it disabled as you suggested in commit 3bb8af8. It's not worth further hassle in my opinion!

Am I right that we have some of the issues you mention after the runner ubuntu upgade in all open PR's? If so, that's even more a reason to live with the bash-completion issue and move on with merging this one. It's good to go in my opinion. Thanks!

[snejus]

Am I right that we have some of the issues you mention after the runner ubuntu upgade

Yes, completely. Just let me know what do you think regarding removing the "bw" colors configuration to introduce coloring to the code blocks and we go ahead with the merge!

[snejus]

For now I'll make it colored - let me know if there's an issue and we can undo this :)

[JOJ0]

For now I'll make it colored - let me know if there's an issue and we can undo this :)

That's absolutely fine. I don't have a strong opinion about whether we have colored syntax highlighting or the black/white style. As far as I remember I chose this style because we didn't have colors before my theme changes to the pydata theme and I liked it esthetically.

Thanks for merging this quickly! I was not available yesterday for an answer.