TST, CI: Skip platform dependent array API failures + adding windows and macOS env in CI

[prady0t]

Closes: #238

[ev-br]

Ah, you're adding the new CI runs here... because I did not press the green button. OK, let's carry on in this PR then.

[prady0t]

Two new failures in CI

macOS:

array_api_tests/test_special_cases.py::test_unary[atanh(real(x_i) is NaN and isfinite(imag(x_i))) -> NaN + NaN j] - AssertionError: out=(nan+1.5707963267948966j), but should be NaN + NaN j [atanh()]

Windows:

array_api_tests/test_creation_functions.py::test_arange - AssertionError: out.dtype=int64, should be default integer dtype int32 [arange()]

array_api_tests/test_creation_functions.py::test_full - AssertionError: out.dtype=int64, should be default integer dtype int32 [full()]

[prady0t]

On my machine (macOS 26.5.1) it passed

array_api_tests/test_special_cases.py::test_unary[atanh(real(x_i) is NaN and isfinite(imag(x_i))) -> NaN + NaN j] PASSED

For test on windows:

full((),0) and arange(0,0) are problematic.

[ev-br]

Now that data-apis/array-api-tests#454 implemented support for multiple skip files, would be best to move platform-specific xfails to the new ...-macos-xfail.txt files.