chore: bump to Python 3.14.0b1

[reneleonhardt]

Description:

• Bump 3.14.0-alpha.6 to 3.14.0-beta.1
• Add 3.13.3t to freethreaded tests

Check list:

• Mark if documentation changes are required.
• Mark if tests were added or updated to cover the changes.

[reneleonhardt]

For what it's worth after ignoring open pull requests:
https://pythoninsider.blogspot.com/2025/07/python-314-release-candidate-1-is-go.html#call-to-action

Tuesday, July 22, 2025

Call to action

We strongly encourage maintainers of third-party Python projects to prepare their projects for 3.14 during this phase, and where necessary publish Python 3.14 wheels on PyPI to be ready for the final release of 3.14.0, and to help other projects do their own testing.

$ act --container-architecture linux/amd64 -P ubuntu-latest=-self-hosted -j lint -W .github/workflows/ci.yaml
::error::The version '3.14' with architecture 'arm64' was not found for macOS 15.6.%0AThe list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json