Patch release for PyPI publishing metadata and release retry safety.
- Adds PyPI project metadata: description, keywords, classifiers, project URLs, SPDX license metadata.
- Bumps package/runtime version to 2.5.1 because PyPI 2.5.0 is already published and immutable.
- Adds skip-existing to the PyPI publish action so accidental reruns do not fail on already uploaded files.
MeXiCOSINT v2.5.0 remains the main feature release. This patch release republishes the same code line with corrected package metadata.