contribute a pull request labeler workflow (#875)

Author: devoncarew

.github/labeler.yml

@@ -0,0 +1,16 @@
+# Configuration for .github/workflows/pull_request_label.yml. 
+
+'infra':
+  - '.github/**'
+
+'package:cronet_http':
+  - 'pkgs/cronet_http/**'
+
+'package:cupertino_http':
+  - 'pkgs/cupertino_http/**'
+
+'package:http':
+  - 'pkgs/http/**'
+
+'package:http_client_conformance_tests':
+  - 'pkgs/http_client_conformance_tests/**'

.github/workflows/pull_request_label.yml

@@ -0,0 +1,22 @@
+# This workflow applies labels to pull requests based on the paths that are
+# modified in the pull request.
+#
+# Edit `.github/labeler.yml` to configure labels. For more information, see
+# https://github.com/actions/labeler.
+
+name: Pull Request Labeler
+permissions: read-all
+
+on:
+  pull_request_target
+
+jobs:
+  label:
+    permissions:
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@5c7539237e04b714afd8ad9b4aed733815b9fab4
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          sync-labels: true