[libc++] Bump machines to latest test suite (#227528)

We recently merged some fixes for the test suite which should make the
comparisons more meaningful. Since we haven't re-generated anything
since the recent LNT machine bumps, re-bumping now should not cause any
churn.

GitOrigin-RevId: 9e4249948a54bf78a5235048cac6c436859a039b