Re-run Milestone Check when Milestones are Applied (#20299)

* re-run when milestones are applied

* update milestone check conditions

.github/workflows/milestone-checker.yml

@@ -10,12 +10,14 @@ on:
     branches:
       - main
       - release/**
+  issues:
+    types: [milestoned, demilestoned]
 
 jobs:
   # checks that a milestone entry is present for a PR
   milestone-check:
     # If there is a `pr/no-milestone` label we ignore this check
-    if: "!contains(github.event.pull_request.labels.*.name, 'pr/no-milestone')"
+    if: "! ( contains(github.event.pull_request.labels.*.name, 'pr/no-milestone') || ( github.event.name == 'labeled' && github.event.label == 'pr/no-milestone' ) )"
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Actions
@@ -30,4 +32,4 @@ jobs:
         uses: ./actions/pr-checks
         with:
           token: ${{secrets.GITHUB_TOKEN}}
-          configPath: configs/milestone-check
+          configPath: configs/milestone-check