Use release/v1 version for the publish gh action

Author: Theofilos Manitaras

.github/workflows/publish.yml

@@ -18,7 +18,7 @@ jobs:
           python -m pip install --upgrade pip setuptools build
           python -m build
       - name: Publish ReFrame to PyPI
-        uses: pypa/gh-action-pypi-publish@master
+        uses: pypa/gh-action-pypi-publish@release/v1
         with:
           verbose: true
           user: __token__