Remove topics frontmatter from REST API autogeneration config (#61341)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: docs-bot

src/rest/lib/config.json

@@ -35,9 +35,6 @@
     "ghec": "ghec"
   },
   "frontmatterDefaults": {
-    "topics": [
-      "API"
-    ],
     "autogenerated": "rest",
     "allowTitleToDifferFromFilename": true
   },