Revert "FIX: public_file_server.enabled is false in test (#8192)" (#8196)

This reverts commit 5a8fdd02fe.

spec/requests/uploads_controller_spec.rb

@@ -266,6 +266,7 @@ describe UploadsController do
     end
 
     it 'returns 200 when js file' do
+      ActionDispatch::FileHandler.any_instance.stubs(:match?).returns(false)
       upload = upload_file("test.js", "themes")
       get upload.url
       expect(response.status).to eq(200)