Use alternative magic-command

Author: kenodegard

.github/workflows/tests.yml

@@ -59,6 +59,7 @@ jobs:
         with:
           label: cla-test
           repository: conda-sandbox/cla
+          magic-command: '@conda-bot test'
           contributor-id: ${{ github.event.pull_request.number }}
           # NOTE: using a real username here will will trigger GH notifications to that user, we wish
           # to avoid that, GH restricts certain keywords, 'login' is one of those restricted keywords