Brush cursor is being drawn even if the selected tool is non-brush in GPv3 paint mode. To prevent this, use `ED_gpencil_brush_cursor_poll` for `pc` poll function. Above poll function returns false if active tool is not brush, this will avoid drawing of paint cursor in `pc->draw`/`grease_pencil_brush_cursor_draw`. Resolves #122541 Pull Request: https://projects.blender.org/blender/blender/pulls/122657