.github: add dependabot to auto-update ci-deps

.github/dependabot.yml

@@ -0,0 +1,10 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    groups:
+      ci-deps:
+        patterns:
+          - "*"

.github/workflows/labeler.yml

@@ -11,7 +11,7 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/labeler@v6.0.0
+    - uses: actions/labeler@v6
       with:
         repo-token: "${{ secrets.GITHUB_TOKEN }}"
         sync-labels: true