ci: Add workflow to update PR labels on successful CI workflow

.github/workflows/update-codemagic-brick-PR-label.yaml

@@ -0,0 +1,34 @@
+name: Update Codemagic Brick PR label in formigas-flutter-bricks
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  update_pr_label:
+    if: startsWith(github.event.head_commit.message, 'Merge pull request') && contains(github.event.head_commit.message, 'from formigas/codemagic-ci-changes-')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Extract PR number
+        id: extract_pr
+        run: |
+          PR_NUMBER=$(echo "${{ github.event.head_commit.message }}" | grep -oP 'from formigas/codemagic-ci-changes-\K\d+')
+          echo "pr_number=$PR_NUMBER" >> $GITHUB_OUTPUT
+      - uses: actions/create-github-app-token@v1
+        id: app-token
+        with:
+          app-id: ${{ secrets.FORMIGAS_APP_ID }}
+          private-key: ${{ secrets.FORMIGAS_APP_PRIVATE_KEY }}
+
+      - name: Add label to PR
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ steps.app-token.outputs.token }}
+          script: |
+            github.rest.issues.addLabels({
+              owner: 'formigas',
+              repo: 'formigas-flutter-bricks',
+              issue_number: ${{ steps.extract_pr.outputs.pr_number }},
+              labels: ['codemagic-ci: success']
+              })