Witch/18th

Effortless Concentration

At 18th level, you learn to maintain some magic effects without concentration. When you cast a spell of 3-points (2nd-level) or lower which normally requires concentration, you need not concentrate on it. When you cast such a spell, you can choose for it to last for its full duration without your concentration, freeing you to concentrate on another effect instead.

Your Flying Broom feature no longer requires concentration to persist.