Use pypa/gh-action-pypi-publish@release/v1 @ GHA

`master` has been sunset quite a while ago and points to a historic version. To use the latest stable release of this action, it should be `release/v1`. The TestPyPI upload uses the right step, but the PyPI one doesn't. This patch corrects that.

Author: webknjaz

.github/workflows/deploy.yml

@@ -50,7 +50,7 @@ jobs:
 
       - name: Publish package to PyPI
         if: github.event.action == 'published'
-        uses: pypa/gh-action-pypi-publish@master
+        uses: pypa/gh-action-pypi-publish@release/v1
         with:
           user: __token__
           password: ${{ secrets.pypi_password }}