Manual:$wgJobQueueIncludeInMaxLagFactor

Whether to include the number of jobs that are queued for the API's maxlag parameter.

Details
The total number of jobs will be divided by this to get an estimated second of maxlag. Typically bots backoff at maxlag=5, so setting this to the max number of jobs that should be in your queue divided by 5 should have the effect of stopping bots once that limit is hit.