When user uses IRSA in EKS the credential file should not be needed.

[reasonerjt]

I've verified the functionality around IRSA in #4959 with the credential file provided.

We want to verify the scenario that when the user uses IRSA on EKS he should not need to provide the credential files

There may be some code changes needed in AWS plugin, we should try to close this gap in v1.12 timeframe.

[reasonerjt]

Submitted PR for AWS plugin:
vmware-tanzu/velero-plugin-for-aws#163

I've verified that the plugin can access s3 and snapshots with this change.

I hit issue #5873 when I'm testing the B/R with Kopia, so I'll keep this issue open until I can verify this case after the work to bump kopia finishes

[reasonerjt]

#6283 is merged to fix the issue on kopia path.

Closing this one.