chore: remove CPE benchmark and cleanup related code #594

Job	Run time
check-branch	11s
check-change	4s
check-base-exist	1s
check-secret	1s
verify_model_training_script	2m 56s
unit-test / unit-test	10m 59s
base-image	1m 5s
s3-image	0s
integration-test-with-exporter / run-integration	10m 5s
integration-test-with-exporter-and-db / run-integration	8m 6s
integration-test-internal-only / run-integration	10m 34s
integration-test-with-latest / run-integration	6m 49s
tekton-test / tekton-test	9m 59s
	1h 0m 50s

Provide feedback