RepositoryStatisticsTest.java:53-58: Refactor...

The puzzle `1663-38685897` from #1663 has to be resolved:

https://github.com/jcabi/jcabi-github/blob/4f39e01db1306736c38a08e7722e1cf20cd37d76/src/test/java/com/jcabi/github/RepositoryStatisticsTest.java#L53-L58

The puzzle was created by volodya-lombrozo on 04-Aug-23.

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).