Relying on a real-time clock like lowres_clock
can be flaky (in particular in debug mode).
Use manual_clock instead to harden the test against
timing issues.
Fixes#20322
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
(cherry picked from commit 32b7cab917)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>