fix: update CLA token

Author: collins-w

.github/workflows/cla.yml

@@ -22,11 +22,17 @@ jobs:
         with:
           egress-policy: audit
 
+      - uses: actions/create-github-app-token@af35edadc00be37caa72ed9f3e6d5f7801bfdf09 # v1.11.7
+        id: gh-app-token
+        with:
+          app-id: ${{ vars.GH_APP_ID }}
+          private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
+
       - name: Checkout Private Repo for Allowlist
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 #v4.2.2
         with:
           repository: OpenZeppelin/cla-sigs
-          token: ${{ secrets.CLA_SIGS_ACCESS_PAT }}
+          token: ${{ steps.gh-app-token.outputs.token }}
           sparse-checkout: |
             allowlist.txt
           sparse-checkout-cone-mode: false