AmazonKeyspacesFixedRateThrottler: Detected a synchronous API call on a driver thread, failing because this can cause deadlocks.

Class `AmazonKeyspacesFixedRateThrottler` doesn't seem to work. The error is,

```
2024-04-23 01:08:22,107 ERROR [main] log.GlueLogger (GlueLogger.scala:error(7)): ERROR: Detected connectivity issue. Check the reference conf file/Glue connection for the source, the job is aborted java.io.IOException: Failed to open native connection to Cassandra at Profile based config at CassandraConnector.conf :: Error instantiating class com.aws.ssa.keyspaces.throttler.AmazonKeyspacesFixedRateThrottler (specified by advanced.throttler.class): Detected a synchronous API call on a driver thread, failing because this can cause deadlocks.
```

Here's the configuration block I'm using,

```
advanced.throttler {
class = com.aws.ssa.keyspaces.throttler.AmazonKeyspacesFixedRateThrottler
max-requests-per-second = 100
number-of-hosts = 3
register-timeout = 15 seconds
}
```

先使用 issue 中所示的 AmazonKeyspacesFixedRateThrottler 設定重現故障，並追蹤 throttler 在何處建立執行個體。確定同步 API 呼叫為何發生在 driver 執行緒上；當設定初始化時不再出現回報的 deadlock prevention 錯誤，即表示完成。

由索引模型根據 Issue 內容生成。