In #96128 we introduced CPU load based range splitting. to control when to split, kv.range_split.load_cpu_threshold was added.

Setting this value too low will result in excessive, destabilizing splitting, given some baseline foreground workload.

This issue is to add a minimum to this setting.

The current default is 500ms. A minimum of 50ms would be reasonable.

Jira issue: CRDB-25080