fix action version

Signed-off-by: Panos Vagenas <[email protected]>

.github/workflows/pypi.yml

@@ -15,7 +15,7 @@ jobs:
   build-and-publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@4
+      - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-poetry
       - name: Build and publish
         run: poetry publish --build --no-interaction --username=__token__ --password=${{ secrets.PYPI_TOKEN }}