relax text test render threshold
relax text test render threshold

so we pass on win as well, see https://github.com/libvips/libvips/commit/981ffe752b3d043d3b1eef48bb6b250da99f958c#r36581177

jcupitt/libvips,lovell/libvips,lovell/libvips,jcupitt/libvips,lovell/libvips,jcupitt/libvips,jcupitt/libvips,lovell/libvips