ci(dependabot): add auto-merge workflow that updates branch before merging

Author: vagabondHustler

.github/workflows/dependabot-auto-merge.yml

@@ -0,0 +1,37 @@
+name: Dependabot auto-merge
+run-name: Dependabot auto-merge
+
+
+on:
+  pull_request:
+    branches:
+      - dev
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    if: github.actor == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fetch Dependabot metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Update branch with latest dev
+        if: steps.metadata.outputs.update-type != 'version-update:semver-major'
+        run: gh pr update-branch "$PR_URL" || true
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Enable auto-merge for patch and minor updates
+        if: steps.metadata.outputs.update-type != 'version-update:semver-major'
+        run: gh pr merge --auto --merge "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}