Resize finalization is executed in a separate topology transition state,
`tablet_resize_finalization`, to ensure it does not overlap with tablet
transitions. The topology transitions into the
`tablet_resize_finalization` state only when no tablet migrations are
scheduled or being executed. If there is a large load-balancing backlog,
split finalization might be delayed indefinitely, leaving the tables
with large tablets.
This PR fixes the issue by updating the load balancer to no schedule any
migrations and to not make any repair plans when there a resize
finalization is pending in any table.
Also added a testcase to verify the fix.
Fixes#21762
Improvement : No need to backport.
Closesscylladb/scylladb#22148
* github.com:scylladb/scylladb:
topology_coordinator: fix indentation in generate_migration_updates
topology_coordinator: do not schedule migrations when there are pending resize finalizations
load_balancer: make repair plans only when there is no pending resize finalization