Issue #, if available: #5099

Description of changes:

• Remove historical job_name caching which causes job name to exceed 63 characters with the addition of the 64 char sha256 hash
• Both TrainingJobName and ProcessingJobName have character limits of 63:
  • https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateProcessingJob.html#sagemaker-CreateProcessingJob-request-ProcessingJobName
  • https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateTrainingJob.html#sagemaker-CreateTrainingJob-request-TrainingJobName
• local artifact hash is now used instead of timestamp in the s3 path to support caching usecases

Testing done:

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