cannot create files and testcases for "Ex" problem in ABC

[aoriso]

This problem happens ABC233 and later ABCs.
In these contest, the name of 8th problem is changed to "Ex" while the URL's letter is "h".

The "run" function of new.rs creates "file_paths", the vector of pair of src path and testcase path.
At the moment of the creation, the order of src_path is alphabetical order, while testcase is problem order.
This makes unexpected "file_paths" variable like this: [ ... (e.rs, e.yml), (ex.rs, f.yml), (f.rs, g.yml), (g.rs, ex.yml)]