Remove mesh triangles in contour plot

From Removing unwanted appearance of underlying mesh, which is a duplicate:

ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, 
 Contours -> {1.0, 4.0, 10.5}, ContourStyle -> None, 
 ContourShading -> {RGBColor[1, .2, 0, .1], RGBColor[1, .2, 0, .3], 
   RGBColor[1, .2, 0, .5], RGBColor[1, .2, 0, .7]}, 
 Method -> {"TransparentPolygonMesh" -> True}]

The mesh comes from reducing the opacity. To avoid the mesh, use fully opaque colors.

$Version

(* "12.1.1 for Mac OS X x86 (64-bit) (June 19, 2020)" *)

Clear["Global`*"]

ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10},
 Contours -> {1.0, 4.0, 10.5},
 ContourStyle -> None,
 ContourShading ->
  {LightRed, Pink, Red, Darker[Red]}]