[rozyczko]

Updated pixi.lock to the newest version.

Added .github/workflows/pypi-publish-check.yml, a workflow that:

• Simulates a PyPI release build on pull requests to master without uploading artifacts.
• Verifies that pixi.lock is up to date and not modified by the environment setup.
• Ensures the working tree is clean before building, preventing accidental inclusion of uncommitted changes.
• Checks that built package versions do not contain local version identifiers (e.g., +dirty), which are rejected by PyPI.
• Runs twine check on the built packages to validate metadata compliance.

[damskii9992]

Erm, shouldn't you just have added --frozen to the setup-pixi action that is run before the build action?