- run_without_leak_tests: have been disabled for months
- build_benchmark: the tooling work here is mostly done and we're not tracking further improvements, free up more devicelab capacity
- system_debug_ios: does not work post iOS13
- mac_enable_twc: not adding more mac tests to devicelab
- hello_world_start_up: disabled

Any tests that we think will be valuable in the future can be resurrected from the git history.