compaction/scrub: register sstables for compaction before validation
When `scrub --validate` runs, it collects all candidate sstables at the
start and validates them one by one in separate compaction tasks.
However, scrub in validate mode does not register these sstables for
compaction, which allows regular compaction to pick them up and
potentially compact them away before validation begins. This leads to
scrub failures because the sstables can no longer be found.
This patch fixes the issue by first disabling compaction, collecting the
sstables, and then registering them for compaction before starting
validation. This ensures that the enqueued sstables remain available for
the entire duration of the scrub validation task.
Fixes#23363
This reported scrub failure occurs on all versions that have the
checksum/digest validation feature for uncompressed sstables.
So, backport it to older versions.
Closesscylladb/scylladb#26034
* github.com:scylladb/scylladb:
compaction/scrub: register sstables for compaction before validation
compaction/scrub: handle exceptions when moving invalid sstables to quarantine