Change to Job Scheduling on Polaris

We have implemented a change to the job scheduling policy on Polaris that affects the prod queues. We have reduced the maximum wall-time on the small, medium, backfill-small, and backfill-medium prod queues. In addition, the minimum node count for the large and backfill-large queues has been increased to 20% capability threshold of 100 nodes (up from 50 nodes). For details on the new wall-time and node count limits, visit: https://docs.alcf.anl.gov/polaris/running-jobs/#queues