Add in the new radius size

Author: lainsce

Helium/gtk-4.0/_tauos.scss

@@ -120,6 +120,9 @@
 .x-large-radius {
   border-radius: 12px;
 }
+.xx-large-radius {
+  border-radius: 24px;
+}
 .circle-radius {
   border-radius: 50%;
 }