Bootstrap or replace can take a long time, but
since feef7d3fa1,
the stop_signal is checked only in checkpoints,
and in particular, abort isn't requested during
join_cluster.
Fixes#23222
* requires backport on top of https://github.com/scylladb/scylladb/pull/23184Closesscylladb/scylladb#23306
* github.com:scylladb/scylladb:
main: allow abort during join_cluster
main: add checkpoint before joining cluster
storage_service: add start_sys_dist_ks