8e9c7397c5 made `rs` a reference, which can
lead to use-after-free. The `normal_nodes` map containing the referenced
value can be destroyed before the last use of `rs` when the topology state
is reloaded after a context switch on some `co_await`. The following move
assignment in `storage_service::topology_state_load` causes this:
```
_topology_state_machine._topology = co_await _sys_ks.local().load_topology_state(tablet_hosts);
```
This issue has been discovered in next-2026.1 CI after queueing the
backport of #28558. `test_truncate_during_topology_change` failed after
ASan reported a heap-use-after-free in
```
co_await _repair.local().bootstrap_with_repair(get_token_metadata_ptr(), rs.ring.value().tokens, session);
```
This test enables `delay_bootstrap_120s`, which makes the bug much more
likely to reproduce, but it could happen elsewhere.
No backport needed, as the only backport of #28558 hasn't been merged yet.
The backport PR will cherry-pick this commit.
Closesscylladb/scylladb#28772