ci: Update pypa/gh-action-pypi-publish to v1.12.3

* Avoid metadata regression in older unsupported releases.
   - c.f. https://github.com/pypa/gh-action-pypi-publish/releases/tag/v1.12.3

Author: matthewfeickert

.github/workflows/pypi.yaml

@@ -63,6 +63,6 @@ jobs:
 
     - name: Publish distribution 📦 to PyPI
       if: github.repository == 'ssl-hep/ServiceX_frontend'
-      uses: pypa/gh-action-pypi-publish@v1.8.14
+      uses: pypa/gh-action-pypi-publish@v1.12.3
       with:
         print-hash: true