[GitHub][UX] Use “Unix-like” instead of “*nix”

[alexislefebvre]

A bot add a comment to PRs, this comment contains this:

# On *nix and Mac

I use Linux for years but I had to search what *nix was.

I suggest to use an simpler word instead:

# On Unix-like and Mac

This is the name of the Wikipedia article: https://en.wikipedia.org/wiki/Unix-like

I didn't found where this text was written.

[OskarStark]

If it makes things more clear, why not

WDYT @nicolas-grekas ?

[derrabus]

Doesn't macOS count as Unix-like as well? 🙃

[alexislefebvre]

It may be rewritten to use names of the actual OSes families:

# On BSD, Linux and macOS

[nicolas-grekas]

The code is here: https://github.com/symfony-tools/recipes-checker/blob/main/src/DiffRecipeVersionsCommand.php
PR welcome