[Eduardo Villalpando Mello (edvilme)]

Summary

• Add a weekly (Monday 12:00 UTC) and manually dispatchable check for the latest published Python release-candidate series.
• Compare major.minor against every explicit python matrix in .github/workflows/pr-check.yml and .github/workflows/build.yml; patch and prerelease/dev variants count as the same series, while floating 3.x entries do not declare RC coverage.
• Create a deduplicated issue with debt and python-version labels when any explicit matrix lacks the series. Include a checklist for both workflows and compatibility testing, preserving minimum-version/build-runtime pins.
• Leave the current CI matrices unchanged. No agent autoassignment or additional credentials are included.

Validation

• python -m pytest -q build/test_update_python_versions.py: 23 passed.
• Black, isort, flake8 and workflow Prettier checks passed.
• Exercised the actual CI layouts, requiring every explicit matrix to contain the series, including individual omission checks.
• Eight mocked Bash scenarios passed: checker output/no update/failure, issue creation with two version values, duplicate suppression, issue-creation failure and API failure. No live test issues were created.

Closes #26263