ci: add workflow to update the release branch.

.github/workflows/update-release.yml

@@ -0,0 +1,19 @@
+name: Update Release Branch
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+jobs:
+  update-release-branch:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Update release branch
+        run: |
+          git push origin ${{ github.ref_name }}:release