Oneliner for T97961. Square sculpt brushes no longer fit
inside the radius circle, they now use the radius for
the square size.
{F13082514}
Note: original patch was modified to scale PBVH
search radius to avoid artifacts.
Differential Revision: https://developer.blender.org/D14974
Reviewed By: Joseph Eagar & Julien Kaspar
Ref: D14974