Pin version of the pypi publish step

Author: rkoopmans

.github/workflows/ci-cd.yml

@@ -100,7 +100,7 @@ jobs:
         python -m venv wheel_env
         ./wheel_env/bin/pip install dist/tinify*.whl
     - name: Publish package to PyPI
-      uses: pypa/gh-action-pypi-publish@master
+      uses: pypa/gh-action-pypi-publish@release/v1
       with:
         user: __token__
         password: ${{ secrets.PYPI_ACCESS_TOKEN }}