Revert "Export all missing modules in compat (#4006)" (#4032)

This reverts commit e0adf90453cca66fdafcddcbbcfcaf9d5bdea17f.

Author: imorland

js/src/forum/compat.ts

@@ -29,9 +29,3 @@ app.initializers.add('subscriptions', function () {
     });
   });
 });
-
-// Expose compat API
-import subscriptionsCompat from './compat';
-import { compat } from '@flarum/core/forum';
-
-Object.assign(compat, subscriptionsCompat);