Refs #20686
Refs #15607
In #15060 we added forced new commitlog segment on user initated flush,
mainly so that tests can verify tombstone gc and other compaction related
things, without having to wait for "organic" segment deletion.
Schema commitlog was not included, mainly because we did not have tests
featuring compaction checks of schema related tables, but also because
it was assumed to be lower general througput.
There is however no real reason to not include it, and it will make some
testing much quicker and more predictable.
Closesscylladb/scylladb#20691
60f8a9f39d