Fix compatibility with Ruby 3.4+.

Author: ioquatix

test/utopia/controller/respond.rb

@@ -63,7 +63,7 @@ def mock_request(*arguments)
 
 		expect(status).to be == 200
 		expect(headers["content-type"]).to be == "text/plain"
-		expect(body.join).to be == "{:user_id=>10}"
+		expect(body.join).to be == {user_id: 10}.to_s
 	end
 end