Fetch tags when checking out repo in GH action.

This will hopefully be enough for `setuptools-scm` to create the
version string.

Author: itsjohncs

.github/workflows/publish-to-pypi.yml

@@ -9,6 +9,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        fetch-tags: true
     - name: Set up Python
       uses: actions/setup-python@v5
       with: