refrax_client_test.go:30-31: Enable...

The puzzle `81-401cd0e2` from #81 has to be resolved:

https://github.com/cqfn/refrax/blob/c7193f948189b0cfb10788fd3149b0c6c0f25a40/internal/client/refrax_client_test.go#L30-L31

The puzzle was created by @volodya-lombrozo on 04-Aug-25.

Estimate: 90 minutes, role: DEV.

If you have any technical questions, don't ask me, submit new tickets instead. The task will be \"done\" when the problem is fixed and the text of the puzzle is _removed_ from the source code. Here is more about [PDD](http://www.yegor256.com/2009/03/04/pdd.html) and [about me](http://www.yegor256.com/2017/04/05/pdd-in-action.html).