The table::take_snapshot() touches the snapshot directory, which is
good. It happens on all shards, which is not that good, because all
shards just step on each other toes when doing it, the directory is not
sharded. Same for post-snapshot directory sync -- it can happen once,
after all shards finish creating snapshot links.
Move both, touching and syncing up one level. There's only one caller of
the method, so only one caller to update.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#24154