ci(workflows): pin 3rd party actions

Author: caugner

.github/workflows/new-issues.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: initial labelling
-        uses: andymckay/labeler@master
+        uses: andymckay/labeler@3a4296e9dcdf9576b0456050db78cfd34853f260 # master
         with:
           add-labels: "needs triage"
           ignore-if-assigned: true