Remove calls to detect-outliers from performance tasks

The performance tests currently call detect-outliers at the end of their runs. This has recently been causing the performance tasks to timeouts due to the command trying to analyze too much data. We aren't currently even using the detect-outliers data to do anything and future performance analysis enhancements will come via expanded metrics, not these legacy scripts, so we should be able to safely just remove the call to detect-outliers.