fix artifact not being cleaned up

[rd-pong]

Issue #, if available:

• Artifacts are not cleaned up after testing. And we are getting errors:

botocore.errorfactory.ResourceLimitExceeded: An error occurred (ResourceLimitExceeded) when calling the CreateArtifact operation: The account-level service limit 'Total number of artifacts allowed, excluding those automatically created by SageMaker' is 6000 Artifacts, with current utilization of 6000 Artifacts and a request delta of 1 Artifacts.

Description of changes:

• Added clean up logic after running log_artifact.

Testing done:
integ test

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