Pin pypi-publish action to v1.12.4

v1.13.0 introduced Docker container name issues with uppercase
repository names. Pin to v1.12.4 which was working previously.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/actions/publish-pypi/action.yml

@@ -16,7 +16,7 @@ runs:
       working-directory: ./Server
 
     - name: Publish distribution to PyPI
-      uses: pypa/gh-action-pypi-publish@release/v1
+      # Pin to v1.12.4 to avoid Docker container name issue with uppercase repo names in v1.13.0+
+      uses: pypa/gh-action-pypi-publish@v1.12.4
       with:
         packages-dir: Server/dist/
-        attestations: false