Fix Auto Label PRs: migrate labeler config to actions/labeler@v5 schema

.github/labeler.yml

@@ -0,0 +1,17 @@
+# Auto-label rules based on files changed in a PR
+
+first-contribution:
+  - changed-files:
+      - any-glob-to-any-file:
+          - "Contributors.md"
+
+documentation:
+  - changed-files:
+      - any-glob-to-any-file:
+          - "*.md"
+          - "docs/**"
+
+github-config:
+  - changed-files:
+      - any-glob-to-any-file:
+          - ".github/**"

.github/workflows/labeler.yml

@@ -0,0 +1,21 @@
+name: Auto Label PRs
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  label:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Auto Label
+        uses: actions/labeler@v5
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          configuration-path: .github/labeler.yml
+          sync-labels: false
+          dot: true