test_tensor_abort_cache_invalidated_on_binary_mtime_change bumped mtime by a
single nanosecond. NTFS stores timestamps as 64-bit FILETIME values in 100ns
ticks, so on Windows that bump rounds away, st_mtime_ns reads back unchanged,
the cache key is identical and the stale abort is inherited, and the assertion
sees True where it wants False.
1ms is still a same-second, sub-second change and is exactly representable, so
the case the test exists to cover actually runs. Skip when the filesystem cannot
record any sub-second change at all rather than asserting product behaviour the
platform cannot exercise.
Not caught before because both jobs in studio-backend-ci.yml are
runs-on: ubuntu-latest, so the studio backend tests only ever run on Linux.