TST: abi3t test extension needs to be updated once meson abi3t support improves

[ngoldbaum]

Currently our test extension manually sets Py_TARGET_ABI3T because meson doesn't yet officially support abi3t and this causes issues. Once meson and meson-python gain a UI for creating abi3t extensions, we need to update our tests to use that API:

numpy/numpy/_core/tests/examples/limited_api/meson.build

Line 76 in cd490dc

'-DPy_TARGET_ABI3T=0x030F0000',

Additionally, we should remove the skips for GIL-enabled Python on Windows whenever meson adds support for the new python3t.lib and python3t.dll files in the Windows distribution.

numpy/numpy/_core/tests/examples/limited_api/meson.build

Line 69 in cd490dc

(host_machine.system() != 'windows' or (py.get_variable('Py_GIL_DISABLED', 0) == 1))

numpy/numpy/_core/tests/test_limited_api.py

Lines 106 to 109 in cd490dc

	@pytest.mark.skipif(
	sys.platform == "win32" and not sysconfig.get_config_var('Py_GIL_DISABLED'),
	reason=("Meson does not yet support building abi3t extensions on the "
	"GIL-enabled build")