Added a workflow to update Appraisal files on dependabot MRs

.github/workflows/dependabot.yml

@@ -0,0 +1,27 @@
+name: StandardRB
+
+on:
+  pull_request:
+    types: [labeled]
+
+jobs:
+  build:
+    if: contains(github.event.pull_request.labels.*.name, 'bundler')
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: true
+      matrix:
+        ruby-version:
+          - "3.2"
+
+    name: Appraisal - Ruby ${{ matrix.ruby-version }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+      - name: Update Appraisal gemfiles
+        run: |
+          bundle exec appraisal update