Fix Henry's ingestion

[philmcmahon]

Todo:

• - deploy 'fix' for s3 issue
• - fix fake failures
• - Allow rendering of > 4000 files
• - Test to see if transcription now working - try 10, 100, 1000 etc
• Deduplicate files in the workspace
• - Investigate dead letter issue (Always send failed transcription tasks to dead letter queue #506 might be relevant) - we should have a message in the dead letter queue for every failure
• - Check transcription service errors - did it fail for any of the 4000 files yesterday? Why?

[philmcmahon]

Doc here: https://docs.google.com/document/d/1hpGX7svv7QXpZb5t83XcS480Dxd_yTiVE_z9Z1h3EQs/edit?tab=t.0