fix(docs): add missing newline at end of JSON files

- Added a newline at the end of the `admin.json` and `server.json` files to comply with JSON formatting standards. This change ensures better compatibility with various parsers and tools that expect a newline at the end of files.

Author: mantrakp04

docs-mintlify/openapi/admin.json

@@ -11365,4 +11365,4 @@
       }
     }
   }
-}
+}

docs-mintlify/openapi/server.json

@@ -10616,4 +10616,4 @@
       }
     }
   }
-}
+}