Automatically label PRs based on *closing* issues (#7547)

* port label sync from pymc-marketing

* use published action

* add likely labels

Author: williambdean

.github/workflows/pr-auto-label.yml

@@ -0,0 +1,19 @@
+name: "Pull Request Labeler"
+on:
+- pull_request_target
+
+jobs:
+  sync:
+    permissions:
+      contents: read
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+    - name: Sync labels with closing issues
+      uses: wd60622/[email protected]
+      with:
+        exclude: "help wanted,needs info"
+      env:
+        GH_TOKEN: ${{ github.token }}