build: remove unused config (#1990)

scripts/vitest/next-config-mock.ts

@@ -8,12 +8,7 @@ export default function getConfig() {
       editorVersion: 'UNKNOWN',
       serverAPI: 'http://127.0.0.1:3000/',
       enableBroadCastChannelProvider: true,
-      enableIndexedDBProvider: true,
       enableDebugPage: true,
-      prefetchWorkspace: false,
-      exposeInternal: true,
-      enableSubpage: true,
-      enableChangeLog: true,
     },
   };
 }