Fix internal tests invoked from zsh shell

[haxoza]

Before this fix some of the internal hatch tests were failing when invoked from zsh shell. This change updates the test fixture to use the same shell detection mechanism as in the actual hatch code.

One of the test errors before the fix:

E       AssertionError: expected call not found.
E       Expected: append('/private/var/folders/q3/s01nm0vn50n3696zg_w711yr0000gn/T/tmpuovbeire/data/pythons/pypy3.9/pypy3.9-v6.3.15-macos_arm64/bin', shells=['sh'])
E         Actual: append('/private/var/folders/q3/s01nm0vn50n3696zg_w711yr0000gn/T/tmpuovbeire/data/pythons/pypy3.9/pypy3.9-v6.3.15-macos_arm64/bin', shells=['zsh'])
E
E       pytest introspection follows:
E
E       Kwargs:
E       assert {'shells': ['zsh']} == {'shells': ['sh']}
E
E         Differing items:
E         {'shells': ['zsh']} != {'shells': ['sh']}
E         Use -v to get more diff

[ofek]

Thanks!

[ofek]

I would prefer if we could please put the return type directly on the function without a dedicated type alias.

[ofek]

I'm going to revert this part because we want this conditional to prevent the shell detection logic for performance reasons.

[ofek]

Thanks again!

[haxoza]

Thanks for merging it and your feedback, I appreciate! I'm sorry I didn't improve the PR myself but I was on my way back home from PyCon.

[ofek]

No worries, it was a fun conference!