Aside from moving the lights from phase A to phase B, or upgrading the service so that the dishwasher load won't appreciably effect the available voltage to the lights, or reducing the load to the lighting circuit by sharing the circuits, I guess the only thing is to reduce the draw on the dishwasher. Can the dishwasher be connected 240 volts? How about 3 phase?
If the PoCo Xfmr is shared, the loads at the neighbors house can cause the lights to flicker and dim. I the dwelling is at or near the end of the Poco ckt this can happen too. This may not be the problem but, you could be chasing ghosts.