Fix Registrator comment trigger to work on commits, not issues/PRs

Author: mtfishman

.github/workflows/Registrator.yml

@@ -7,9 +7,7 @@ on:
       - "main"
     paths:
       - "Project.toml"
-  issue_comment:
-    types:
-      - "created"
+  commit_comment:
 permissions:
   contents: "write"
   pull-requests: "write"