Fix #129116: Texture Paint Line stroke preview does not show up

Custom paint overlays (smooth stroke & line stroke) do not show up if
a specific cursor is set for the tool.

Pull Request: https://projects.blender.org/blender/blender/pulls/129132

scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -1975,7 +1975,6 @@ class _defs_texture_paint:
             idname="builtin.brush",
             label="Paint",
             icon="brush.sculpt.paint",
-            cursor='PAINT_CROSS',
             options={'USE_BRUSHES'},
         )