[libc++abi] Temporarily disable test on Apple to fix the CI

This test has been failing on some SDKs for a long time because we lack
a proper way of identifying the SDK version in Lit. Until that is possible,
mark the test as unsupported on Apple to restore the CI.

GitOrigin-RevId: fc9865c4a76ed3bbec77da34529e01e64006fed3
1 file changed