In several exception handlers, only raft::request_aborted was being
caught and rethrown, while seastar::abort_requested_exception was
falling through to the generic catch(...) block. This caused the
exception to be incorrectly treated as a failure that triggers
rollback, instead of being recognized as an abort signal.
For example, during tablet draining, the error log showed:
"tablets draining failed with seastar::abort_requested_exception
(abort requested). Aborting the topology operation"
This change adds seastar::abort_requested_exception handling
alongside raft::request_aborted in all places where it was missing.
When rethrown, these exceptions propagate up to the main run() loop
where handle_topology_coordinator_error() recognizes them as normal
abort signals and allows the coordinator to exit gracefully without
triggering unnecessary rollback operations.
Fixes: scylladb/scylladb#27255
(cherry picked from commit 37e3dacf33)
Closesscylladb/scylladb#27663