Use a stable version of the pypi publish action

Author: stchris

.github/workflows/build.yml

@@ -40,7 +40,7 @@ jobs:
           python setup.py sdist bdist_wheel
       - name: Publish a Python distribution to PyPI
         if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
-        uses: pypa/gh-action-pypi-publish@master
+        uses: pypa/gh-action-pypi-publish@release/v1
         with:
           user: __token__
           password: ${{ secrets.pypi_password }}