weird span stack in meta service log

[BugenZhao]

When launching the playground, sometimes we may see such logs:

2024-11-07T17:56:49.936913+08:00  INFO      rw-standalone-meta bootstrap_recovery:recovery_attempt: risingwave_meta::hummock::compactor_manager: Added compactor session 2
2024-11-07T17:56:49.937148+08:00  INFO      rw-standalone-meta bootstrap_recovery:recovery_attempt: risingwave_meta::hummock::manager::compaction: compactor 2 enters the cluster

These logs should not appear within bootstrap_recovery and recovery_attempt spans. I suppose it's because the spans are misused somewhere in async context, which results in the thread-local context for recording the span stack not being properly cleaned up.