[BUG] Chunk Data Not Being Saved to S3 Bucket in v2.3.0

[mixchazuke]

🐞Describe the bug

In version 2.3.0, chunk data is being registered as null. This issue did not occur in versions prior to v2.3.0.

🔄 To Reproduce

Steps to reproduce the behavior:

1.Use the application in version 2.3.0

📷 Screenshots

・Execute a SQL query in Athena to retrieve chatbot conversation data.

・Verify the S3 bucket contents and observe that the chunk data is registered as null.

　・Before v2.3.0:
　　- d.newimage.MessageMap.S
　　　used_chunks:[{"content":~~~~~}]
　・v2.3.0:
　　- d.newimage.MessageMap.S
　　　used_chunks: null

🔎 Logs for Chat Issues

🔎 Logs for Bot Creation/Update Issues

📝 Additional context

Chunk data is really helpful for making chatbot answers better. I'd love to see the ability to register chunk data in v2.3.0.