Use MATZBOT_GITHUB_TOKEN

Author: k0kubun

.github/workflows/auto_request_review.yml

@@ -12,4 +12,4 @@ jobs:
       - name: Request review based on files changes and/or groups the author belongs to
         uses: necojackarc/auto-request-review@v0.7.0
         with:
-          token: ${{ secrets.KOKUBUN_GITHUB_TOKEN }}
+          token: ${{ secrets.MATZBOT_GITHUB_TOKEN }}