ci: add pull request labeler

Author: brianheineman

.github/workflows/pr-labeler.yml

@@ -0,0 +1,20 @@
+name: Pull request labeler
+
+on:
+  pull_request_target:
+    types: [opened, edited]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  main:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Label pull request
+        uses: release-drafter/release-drafter@v5
+        with:
+          disable-releaser: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}