Update await-fast-ci.yaml

Author: kliao-csa

.github/workflows/await-fast-ci.yaml

@@ -38,6 +38,6 @@ jobs:
           curl -L \
           -X POST \
           -H "Accept: application/vnd.github+json" \
-          -H "Authorization: Bearer ${{ secrets.JOB_CANCEL_PAT }}" \
+          -H "Authorization: Bearer ${{ secrets.MATTER_PAT }}" \
           -H "X-GitHub-Api-Version: 2022-11-28" \
           https://api.github.com/repos/project-chip/connectedhomeip/actions/runs/${{ github.run_id }}/cancel