chore(deps): update actions/github-script action to v7

Author: unity-renovate[bot]

.github/workflows/backport-verification.yml

@@ -21,7 +21,7 @@ jobs:
         uses: actions/checkout@v3
 
       - name: Check PR description
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         with:
           script: |
             const pr = context.payload.pull_request;