Docs: Migrate developer walkthrough to Meson

[tobiasdiez]

Migrates the developer walkthrough to use meson (on top of conda) for the easist and most modern setup. Also streamlined the instructions a bit. Moreover, the main installation page now simply refers to the developer walkthrough for the dev setup. Finally, a few outdated info about binaries and linux distro is removed.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[tobiasdiez]

@dimpase this should implement the changes we discussed in another PR recently.

[user202729]

Supersedes #39515 , I suppose.

[dimpase]

something is going on with docbuild:

#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] building [html]: targets for 8 source files that are out of date
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] updating environment: [config changed ('version')] 6 added, 0 changed, 2 removed
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/conda.rst: WARNING: document isn't included in any toctree
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/launching.rst: WARNING: document isn't included in any toctree
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/meson.rst: WARNING: document isn't included in any toctree
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/source.rst: WARNING: document isn't included in any toctree
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/troubles.rst: WARNING: document isn't included in any toctree
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] /sage/src/doc/en/installation/source.rst:267: WARNING: undefined label: 'installation-guide-windows' [ref.ref]
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] [installat] The HTML pages are in ../../local/share/doc/sage/html/en/installation.
#30 4659.0   [sagemath_doc_html-none]   [spkg-install] Error building the documentation.

[dimpase]

now, this should fix it

[dimpase]

building doc still fails:

[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/conda.rst: WARNING: document isn't included in any toctree
[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/launching.rst: WARNING: document isn't included in any toctree
[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/meson.rst: WARNING: document isn't included in any toctree
[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/source.rst: WARNING: document isn't included in any toctree
[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/troubles.rst: WARNING: document isn't included in any toctree
[sagemath_doc_html-none] [spkg-install] [installat] /sage/src/doc/en/installation/source.rst:267: WARNING: undefined label: 'installation-guide-windows' [ref.ref]

[github-actions]

Documentation preview for this PR (built with commit 5f6adad; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[tobiasdiez]

Docs build now nicely, so this is ready for review.

[tobiasdiez]

Supersedes #39515 , I suppose.

Actually not, I tried to make the changes here orthogonal to that PR.

[dimpase]

@sagemath/core there is still

test-new Expected — Waiting for status to be reported

hang in CI, but no reaction, despite it was already mentioned at least once.
Only few members of @sagemath/core are actually active in the project, and of these who are, only very few are maintainers.
(e.g. I'm in the team, but I am not a maintainer)

The latter should be addressed - if you, as a maintainer, cannot react quickly on requests only you can deal with, you need to get more maintainers.