fix: ignore non-executable files in check_shellscript_set_options.py

[lukasoyen]

No description provided.

[hofbi]

Instead of extending the separation function which should be only about separation, I would suggest to do the filtering here first

Suggested change

	are_all_files_valid, bash_files, sh_files = _separate_bash_from_sh_files(args.filenames)
	executable_files = [filename for filename in args.filenames if _is_executable(filename)]
	are_all_files_valid, bash_files, sh_files = _separate_bash_from_sh_files(executable_files)

If you want to unit test this, you could also move the list comprehension into a small function

[hofbi]

@cbachhuber I was too slow, but could be a follow up PR. I still think that separation and executable filtering are 2 different tasks.

[lukasoyen]

The logic is more intricate. We ultimately want to find out if the script is bash or sh. But we don't necessarily care about if it is executable or has a shebang. We only use the shebang to determine the language.

So if we now filter executable first, we would filter out files that are non-executable, but have a shebang and would have been flagged before.

[hofbi]

But scripts that are not executable could be considered as "libraries" and don't need a shebang

[lukasoyen]

But we still want the set ... for them right?

[hofbi]

If they are considered as libraries I think they get what the executing script defines