[BUG] DynamoDB source shard does not exist results in stuck pipeline

Describe the bug
There are times when this error is received by the DynamoDB source when it is getting a shard iterator for a shard (https://github.com/opensearch-project/data-prepper/blob/9f778dde31ca25ce69ebd61bcd97b6a6c1c4cd3b/data-prepper-plugins/dynamodb-source/src/main/java/org/opensearch/dataprepper/plugins/source/dynamodb/stream/ShardConsumerFactory.java#L170)

2024-04-01T21:32:04.221 [pool-13-thread-4] ERROR org.opensearch.dataprepper.plugins.source.dynamodb.stream.ShardConsumerFactory - Exception when trying to get the shard iterator due to Requested resource not found: Shard does not exist (Service: DynamoDbStreams, Status Code: 400, Request ID: CBIRSDQC1HK3F07CNNNAJ1EOBBVV4KQNSO5AEMVJF66Q9ASUAAJG)

To Reproduce
Have not recreated, but suspicion is that this is due to acknowledgments not being received for shards, and leads to retrying the shard for 24 hours until it expires. However, the pipeline should recover after this, but it does not even though the partition is marked as completed when this error is hit (https://github.com/opensearch-project/data-prepper/blob/9f778dde31ca25ce69ebd61bcd97b6a6c1c4cd3b/data-prepper-plugins/dynamodb-source/src/main/java/org/opensearch/dataprepper/plugins/source/dynamodb/stream/StreamScheduler.java#L124)

Expected behavior
Move on to the next shards and continue processing

Screenshots
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Environment (please complete the following information):

• OS: [e.g. Ubuntu 20.04 LTS]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

Start with ShardConsumerFactory.java at the shard-iterator error location, then trace how StreamScheduler.java handles the completed partition. Check how a missing DynamoDB source shard affects retry and completion state. Done means the pipeline moves to subsequent shards and continues processing after this error.