This reverts commit b97f466438.
It turns out that the schema mechanism has a lot of nuances,
after this change, for unknown reason, it was empirically
proven that the amount of cross shard on an upgraded node was
increased significantly with a steady stress traffic, if
was so significant that the node appeared unavailable to
the coordinators because all of the requests started to fail
on smp_srvice_group semaphore.
This revert will bring back a caveat in Scylla, the caveat is
that creating a table in a mixed cluster **might** under certain
condition cause schema mismatch on the newly created table, this
make the table essentially unusable until the whole cluster has
a uniform version (rolling upgrade or rollback completion).
Fixes#6893.
779502ab11