Refactor GitHub Actions workflow to improve label checking and backport PR handling

Author: TravisEz13

.github/workflows/labels.yml

@@ -1,7 +1,7 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
-name: Verify PR Labels
+name: Check Labels
 
 on:
   pull_request:
@@ -10,16 +10,52 @@ on:
 permissions:
   contents: read
   pull-requests: read
+  issues: write
 
 jobs:
+  label-backport-prs:
+    permissions:
+      contents: read
+      pull-requests: read
+      issues: write
+
+    name: Label Backport PRs
+    if: github.repository_owner == 'PowerShell' && github.event.action == 'opened' && startsWith(github.event.pull_request.base.ref, 'release/v') && startsWith(github.event.pull_request.title, '[release/v')
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Label Original PRs if backport PR
+      continue-on-error: true
+      if: ${{ github.event.action == 'opened' && startsWith(github.event.pull_request.base.ref, 'release/v') && startsWith(github.event.pull_request.title, '[release/v') }}
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const description = github.event.pull_request.body || '';
+          const branch = github.event.pull_request.base.ref;
+          const match = description.match(/\$\$\$originalprnumber:(\d+)\$\$\$/);
+          if (match) {
+            const originalPrNumber = match[1];
+            console.log(`Original PR number found: ${originalPrNumber}`);
+
+            const labelName = branch.replace('release/v', 'backport-') + '.x-migrated';
+            console.log(`labelName: ${labelName}`);
+
+            await github.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: originalPrNumber,
+              labels: [labelName]
+            });
+          } else {
+            console.log("No original PR number found in the description.");
+          }
+
   verify-labels:
+    name: Verify Change Log Labels
     if: github.repository_owner == 'PowerShell'
     runs-on: ubuntu-latest
 
     steps:
-    - name: Check out the repository
-      uses: actions/checkout@v4
-
     - name: Verify PR has label starting with 'cl-'
       id: verify-labels
       uses: actions/github-script@v7
@@ -28,4 +64,5 @@ jobs:
           const labels = context.payload.pull_request.labels.map(label => label.name.toLowerCase());
           if (!labels.some(label => label.startsWith('cl-'))) {
             core.setFailed("Every PR must have at least one label starting with 'cl-'.");
-          }
+
+