Change SBE and Classic Engine build variants back to weekly in both performance and sys-perf. We are running them almost every day to keep the data fresh while we are actively working to improve SBE performance. Once this effort wraps up, we don't need to run the tests as frequently. We can reduce the frequency at that time.

We may ultimately want to eliminate the special build variants in the long run, though I'm guessing that we will want to keep them even after PM-2697 wraps up to help with any follow-up SBE-related projects.