Support free threaded Python versions like '3.13t'

[colesbury]

Python wheels, pyenv, and a number of other tools use 't' in the Python version number to identify free threaded builds. For example, '3.13t', '3.14.0a1', '3.14t-dev'.

This PR supports that syntax in actions/setup-python, strips the "t", and adds "-freethreading" to the architecture to select the correct Python version.

See #771 and actions/python-versions#319

[renxida]

Meanwhile, if you can't wait, here at https://github.com/nod-ai/shark-ai/actions/workflows/ci_linux_x64_nogil-libshortfin.yml

we are using

    - name: Setup Python
      uses: deadsnakes/action@e640ac8743173a67cca4d7d77cd837e514bf98e8 # v3.2.0
      with:
        python-version: "3.13-dev"
        nogil : true

[rgommers]

If anyone needs the functionality in this PR, I'd recommend to use https://github.com/Quansight-Labs/setup-python. That is a fork of this action with the sole purpose of providing the functionality in this PR (free-threading support) until this PR gets merged (see this issue for context).

Data point for reviewers: we've exercised this PR quite heavily by now in projects like NumPy and SciPy, on Linux, macOS and Windows (x86-64 and aarch64/arm64), and it's been working smoothly to date.

[priyagupta108]

Hi @colesbury 👋,
Thank you for your valuable contribution!
During our testing, we observed that the changes in this PR do not support specifying the patch version (e.g., 3.13.1t) for the python-version input for the free-threaded binary. Please ensure that the python-version input values align with the existing input syntax.
Additionally, To keep the documentation up-to-date, please update this PR to incorporate the corresponding documentation updates.

Thank you!

[ddelange]

Also noting here that 3.13 and 3.13t currently don't live happily next to each other on Windows: Quansight-Labs#5 (comment)

[colesbury]

Hi @priyagupta108, thank you for reviewing the PR. I've fixed the handling of versions like 3.13.1t and added a test for that. I've also updated the README and "advanced-usage" documentation.

[priyagupta108]

Hi @colesbury 👋,

Thank you for making the updates! During our testing of this PR, we've identified a few issues related to free-threaded Python version inputs:

• Prerelease Versions: The current changes do not support semver notation for prerelease versions such as alpha, beta, and RC. For example, versions like 3.14.0-alpha.1, 3.14.0-beta.2, and 3.14.0-rc.1 should be supported.
  Additionally, versions such as 3.14.0a1t and 3.14.0ta1 are mentioned in the documentation changes, but they are failing to run as shown in the screenshot below. Please note that the versions 3.14.0a1t and 3.14.0ta1 do not appear to be valid semver notation according to the semver guidelines.
  
  
  

• Version Ranges: Various range syntaxes (e.g., hyphen ranges, x-ranges) are unsupported.

• python-version-file Input: Unable to read the Python version from pyproject.toml. It seems that the python-version-file input is not functioning correctly, as shown in the below screenshot.
  
  

Here is a demo run showcasing prerelease versions, version ranges, and python-version-file input examples. Please ensure that the PR changes support these input syntaxes for free-threaded Python versions.

To ensure full compatibility with all supported Python version formats and inputs including python-version-file input, please address these issues and ensure the implementation fully supports semantic versioning (semver) guidelines to handle different version formats correctly. Additionally, update the documentation to provide clarity on the syntax for free-threaded Python versions.
For details on supported Python version inputs, please refer the action's documentation.

Thank you!