Run URL linter on nightly only (#153157)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/153157
Approved by: https://github.com/malfet

.github/workflows/_link_check.yml

@@ -7,10 +7,14 @@ on:
       ref:
         type: string
         required: true
+      run-url-lint:
+        type: boolean
+        required: false
+        default: false
 
 jobs:
   lint-urls:
-    if: ${{ github.event_name != 'pull_request' || !contains(github.event.pull_request.labels.*.name, 'skip-url-lint') }}
+    if: ${{ inputs.run-url-lint }}
     uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
     with:
       timeout: 120

.github/workflows/nightly.yml

@@ -34,6 +34,7 @@ jobs:
     with:
       runner: ${{ needs.get-label-type.outputs.label-type }}
       ref:    ${{ github.sha }}
+      run-url-lint: true
     secrets: inherit
 
   docs-build: