Adwaita: Tweak padding in checkbutton & radiobutton

Since we can now use border-spacing in checkbutton and radiobutton,
we don't need the margin in check and radio for spacing anymore.

Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/2697

gtk/theme/Adwaita/_common.scss

@@ -2397,16 +2397,12 @@ radiobutton {
 
   &.text-button {
     // this is for a nice focus on check and radios text
-    padding: 4px 2px;
+    padding: 4px;
   }
 }
 
 check,
 radio {
-  margin: 0 4px;
-
-  &:only-child { margin: 0; }
-
   min-height: 14px;
   min-width: 14px;
   border: 1px solid;