Add support for labeled (run validation) pull request events and remove validation label if present

Author: emericklaw

.github/workflows/validate-pull-request.yml

@@ -2,7 +2,7 @@ name: Validate Pull Request
 
 on:
   pull_request:
-    types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened, labeled]
 
 permissions:
   contents: read
@@ -12,8 +12,22 @@ permissions:
 jobs:
   validate-metadata:
     runs-on: ubuntu-latest
+    if: github.event.action != 'labeled' || github.event.label.name == 'run validation'
 
     steps:
+    - name: Remove validation label if present
+      if: github.event.action == 'labeled' && github.event.label.name == 'run validation'
+      uses: actions/github-script@v7
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+        script: |
+          github.rest.issues.removeLabel({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            issue_number: context.issue.number,
+            name: 'run validation'
+          })
+
     - name: Checkout code
       uses: actions/checkout@v4
       with: