Update IRSA and Pod Identity to new sample application version

[niallthomson]

What would you like to be added?

Release 0.8.0 of the sample application now has the cart component check its ability to connect to DynamoDB on startup, including checking its IAM permissions. The workshop should be updated to leverage this flow.

See how the ECS Immersion Day does this here

Why is this needed?

This simplifies the flow of the workshop since you don't need to try to access the application to trigger the error, it will happen when the pod starts.