The glare coming to the neighbors depends on the color of your wall not theirs

Or relocate the light so that it and the wall below it is not in plain sight to the neighbors windows/garden

Then get red walls.
Or mount the yardblaster on a pole to where it would not shine much light on the walls, but lights up the area around the chicken coop.
That's a trick I see around here, but not for chicken coops, which are in the more "Out There" areas.