fix: --f-font-weight-medium variable value (fixes SFKUI-7399)

Author: udenius

packages/theme-default/src/shared/_index.scss

@@ -46,7 +46,7 @@
 
     /// Font weight
     --f-font-weight-normal: 400;
-    --f-font-weight-medium: 700;
+    --f-font-weight-medium: 600;
     --f-font-weight-bold: 700;
 
     /// Font line height