Build wheel, update CI and improve build system

[tobiasdiez]

A few interconnected changes:

• Use uv in CI
• Improve the CI by adding various pre-checks and diagnostic output
• Fix wheel building by using the .install-pari script instead of relying on sage-the-distro to setup the build environement
• Improve that install-pari script to work on more platforms and install the required dependencies (like wget, sudo, ...) if needed
• Require Python 3.12 in line with Spec0 (mostly because I faced build errors with older versions and don't think it was worth the time to fix them)
• Add integration tests that verify that cypari can be used in other cython files
• Improve the detection of the pari datapath: use meson to find it (by using pari_datadir of the pari lib) and then inject it into the autogen

Notes:

• A few changes contain stuff for Windows; they are currently inactive and preparation for Make it compile on Windows #186
• The wheelbuilding on macos uses brew to install pari. As a result, the wheels have a MACOSX_DEPLOYMENT_TARGET >= 13.0 and can thus only be used on relatively modern macos systems. This could be improved in a follow-up by using the install-pari script.

[dimpase]

by the way, I have a testing-related uv (?) question. Suppose I want to test something in a uv venv using a sagemath wheel built on the same machine (with uv build --wheel .). Installing such a wheel into the venv works, sagemath by itself works, but building against so installed sagemath doesn't (at least in setuptools projects, maybe meson et al are better), as it asks for a version known to PyPI, and that's a no-go.
Is there a way to tell the toolchain to skip these sorts of checks?

---

PS. Never mind, TIL about uv build --no-index --no-build-isolation :-)

[dimpase]

are we going with Spec0 for sage 10.8?

[dimpase]

OK. When we get closer to the release, we'll need to update docs about tests etc.

[tobiasdiez]

Thanks for the quick review!

are we going with Spec0 for sage 10.8?

I would say yes, and have opened sagemath/sage#40936 to drop Python 3.11.
But this needs PR needs sagemath/sage#39163 first (ready for review).

OK. When we get closer to the release, we'll need to update docs about tests etc.

While it would be nice to add more developer docs, I don't have the time for this at the moment. (Also the windows support is not likely to happen very soon.)

Thus, from my side at least, now would be a good moment for a release.

[dimpase]

CI tests fail.

[collares]

Should .py be .pc here?

[dimpase]

the name of this file is wrong. pc, not py.
@tobiasdiez @collares

should be fixed