Change GITHUB_TOKEN to use secrets for PR actions

Updated GITHUB_TOKEN to use secrets.GYGROBOT_TOKEN for approvals and merges.

Author: cainelli

.github/workflows/auto-approve.yml

@@ -19,10 +19,10 @@ jobs:
         run: gh pr review --approve "$PR_URL"
         env:
           PR_URL: ${{ github.event.pull_request.html_url }}
-          GITHUB_TOKEN: ${{ github.token }}
+          GITHUB_TOKEN: ${{ secrets.GYGROBOT_TOKEN }}
 
       - name: auto-merge Dependabot PR
         run: gh pr merge --auto --squash "$PR_URL"
         env:
           PR_URL: ${{ github.event.pull_request.html_url }}
-          GITHUB_TOKEN: ${{ github.token }}
+          GITHUB_TOKEN: ${{ secrets.GYGROBOT_TOKEN }}