fixtures: show test as skip location if skipped from an xunit setup function

[bluetech]

PR #10482 made it so that if a fixture calls skip(), the skip location is shown as the test function, not the fixture. But it excluded xunit setup fixtures from this.

I suspect this was done to make a pre-existing test pass, however I think that the same reason for fixtures applies to xunit fixtures just as well, so we shouldn't exclude it.

Would also remove a string-hack that was used to implement this exclusion...

pytest/src/_pytest/fixtures.py

Lines 1162 to 1168 in bf451d4

	try:
	result = call_fixture_func(fixturefunc, request, kwargs)
	except TEST_OUTCOME as e:
	if isinstance(e, skip.Exception) and not fixturefunc.__name__.startswith(
	"xunit_setup"
	):
	e._use_item_location = True