Use sysconfigdata and build-details.json from shared library build

[mgorny]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

Use the sysconfigdata from the shared library build rather than the static one. The main difference is that this ensures that programs link to the shared Python library rather than the static library. Other differences are mostly superficial (build directories, test invocation commands).

Also use the build-details.json from there. Unlike the static build version, it has all the data, including static and shared library, and extension build details.

Fixes #565

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe/meta.yaml:

• ℹ️ The recipe is not parsable by parser conda-souschef (grayskull). This parser is not currently used by conda-forge, but may be in the future. We are collecting information to see which recipes are compatible with grayskull.
• ℹ️ The recipe is not parsable by parser conda-recipe-manager. The recipe can only be automatically migrated to the new v1 format if it is parseable by conda-recipe-manager.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/21076555700. Examine the logs at this URL for more detail.}

[mgorny]

Okay, so:

1. Looks like my change is also causing python3-config --ldflags --embed to link against the dynamic library, which seems reasonable. However, tests need updating for that.
2. Given Move libpython.so to another output #843, perhaps instead of trying to force shared/static from a single test, I'll just split the libraries and test each one separately.

[mgorny]

Oh wait, that's for 3.15+ only.

[mgorny]

Ok, it's green now.

[rgommers]

leftover from debugging?

[mgorny]

No, it's actually used in tests. However, it was listed only for python output and was missing for libpython-static.

[isuruf]

This is gonna make recipes like uWSGI link to the shared python library instead of the static library from a build number bump.