Ensure all git history is available for setuptools_scm

.github/workflows/ci.yml

@@ -69,6 +69,8 @@ jobs:
     steps:
       - name: Checkout Repo
         uses: actions/checkout@v4.1.1
+        with:
+          fetch-depth: 0  # Fetch all refs so setuptools_scm can generate the correct version number
 
       - name: Set up Python ${{ env.LATEST_PYTHON_VER }}
         uses: actions/setup-python@v4.7.1

.readthedocs.yaml

@@ -4,12 +4,15 @@
 
 version: 2
 
-# Set the version of Python and other tools you might need
 build:
   os: ubuntu-22.04
   tools:
     python: "3.11"
   jobs:
+    post_checkout:
+      # RTD defaults to a depth of 50 but Briefcase versioning may require
+      # much more git history to accurately determine the SCM version
+      - git fetch --unshallow
     pre_build:
       - tox -e docs-lint