chore(releasenotes): update workflow configurations (#725)

Add a new trigger for pull-request when a label is added.

Author: puneetbehl

.github/workflows/release-notes.yml

@@ -6,9 +6,9 @@ on:
     branches:
       - '[6-9]+.[0-9]+.x'
   pull_request:
-    types: [opened, reopened, synchronize]
+    types: [opened, reopened, synchronize, labeled]
   pull_request_target:
-    types: [opened, reopened, synchronize]               
+    types: [opened, reopened, synchronize, labeled]               
   workflow_dispatch:
 jobs:
   release_notes:
@@ -46,4 +46,4 @@ jobs:
           name: ${{ env.title }} ${{ steps.release_notes.outputs.next_version }}
           tag: v${{ steps.release_notes.outputs.next_version }}
           bodyFile: CHANGELOG.md
-          token: ${{ secrets.GH_TOKEN }}
+          token: ${{ secrets.GH_TOKEN }}