We see the abort_requested_exception error from time
to time, instead of sleep_aborted that was expected
and quietly ignored (in debug log level).
Treat abort_requested_exception the same way since
the error is expected on shutdown and to reduce
test flakiness, as seen for example, in
https://jenkins.scylladb.com/job/scylla-master/job/scylla-ci/3033/artifact/logs-full.release.010/1691896356104_repair_additional_test.py%3A%3ATestRepairAdditional%3A%3Atest_repair_schema/node2.log
```
INFO 2023-08-13 03:12:29,151 [shard 0] compaction_manager - Asked to stop
WARN 2023-08-13 03:12:29,152 [shard 0] gossip - failure_detector_loop: Got error in the loop, live_nodes={}: seastar::sleep_aborted (Sleep is aborted)
INFO 2023-08-13 03:12:29,152 [shard 0] gossip - failure_detector_loop: Finished main loop
WARN 2023-08-13 03:12:29,152 [shard 0] cdc - Aborted update CDC description table with generation (2023/08/13 03:12:17, d74aad4b-6d30-4f22-947b-282a6e7c9892)
INFO 2023-08-13 03:12:29,152 [shard 1] compaction_manager - Asked to stop
INFO 2023-08-13 03:12:29,152 [shard 1] compaction_manager - Stopped
INFO 2023-08-13 03:12:29,153 [shard 0] init - Signal received; shutting down
INFO 2023-08-13 03:12:29,153 [shard 0] init - Shutting down view builder ops
INFO 2023-08-13 03:12:29,153 [shard 0] view - Draining view builder
INFO 2023-08-13 03:12:29,153 [shard 1] view - Draining view builder
INFO 2023-08-13 03:12:29,153 [shard 0] compaction_manager - Stopped
ERROR 2023-08-13 03:12:29,153 [shard 0] view - start failed: seastar::abort_requested_exception (abort requested)
ERROR 2023-08-13 03:12:29,153 [shard 1] view - start failed: seastar::abort_requested_exception (abort requested)
```
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#15029