Add new automated workflow to update stable tag

When we have a "released" event, which is either:
- publishing a non-draft release
- changing a pre-release to a release

`${{ github.ref }}` will be the new release tag when the event is
triggered.

References:
- https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows#release
- https://docs.github.com/en/webhooks/webhook-events-and-payloads?actionType=released#release
- https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs#github-context

Author: cjreynol

.github/workflows/update-stable-tag.yaml

@@ -0,0 +1,31 @@
+name: Update Stable Tag
+
+on: [pull_request, push]
+  # TODO CJR: change event trigger away from test
+  #release:
+  #  types: [released]
+
+permissions:
+  contents: write
+
+# TODO CJR: s/test_chad/stable
+jobs:
+  update-stable-tag:
+    runs-on: ubuntu-24.04
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+      with:
+        # TODO CJR: why does fetch-tags not seem to pull the tag?
+        fetch-depth: 0
+        fetch-tags: true
+    # TODO CJR: do not think we need this with github.ref
+    - name: Determine build to mark
+       # returns in reverse chronological order by default
+      run:  echo "STABLE=$(git rev-list --tags --max-count=1)" >> $GITHUB_ENV
+    - name: Delete current, local stable tag
+      run:  git tag -d test_chad
+    - name: Create new stable tag
+      run: git tag test_chad $STABLE # TODO CJR use this for final version ${{ github.ref }}
+    - name: Force push to overwrite current stable
+      run: git push -f --tags