fix(ci/cd): use RenkuBot token

Author: leafty

.github/workflows/cleanup-old-deployments.yml

@@ -12,6 +12,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/github-script@v7
         with:
+          github-token: ${{ secrets.RENKUBOT_GITHUB_TOKEN }}
           script: |
             const script = require('./.github/workflows/cleanup-old-deployments.js')
             await script({ core, github })