build: The publish action now does releases so we switch to v1

The build showed this warning:

Warning:  You are using "pypa/gh-action-pypi-publish@master". The "master" branch of this project has been sunset and will not receive any updates, not even security bug fixes. Please, make sure to use a supported version. If you want to pin to v1 major version, use "pypa/gh-action-pypi-publish@release/v1". If you feel adventurous, you may opt to use use "pypa/gh-action-pypi-publish@unstable/v1" instead. A more general recommendation is to pin to exact tags or commit shas.

.github/workflows/pypi-publish.yml

@@ -25,7 +25,7 @@ jobs:
         run: python setup.py sdist bdist_wheel
 
       - name: Publish to PyPi
-        uses: pypa/gh-action-pypi-publish@master
+        uses: pypa/gh-action-pypi-publish@release/v1
         with:
           user: __token__
           password: ${{ secrets.PYPI_UPLOAD_TOKEN }}