used scss @mixin

packages/app/src/components/Sidebar/Skeleton/SidebarSkeleton.module.scss

@@ -7,22 +7,17 @@ $h5-line-height: 18px;
   padding: (($h3-line-height - 16px) / 2) 0;
 }
 
-.grw-sidebar-skeleton-text {
+@mixin grw-sidebar-skeleton-text($width) {
+  max-width: $width;
   height: 1rem;
 }
 
 .grw-sidebar-skeleton-text-medium {
-  max-width: 120px;
-  height: 1rem;
-}
-
-.grw-sidebar-skeleton-text-large {
-  max-width: 200px;
-  height: 1rem;
+  @include grw-sidebar-skeleton-text(120px);
 }
 
 .grw-sidebar-skeleton-text-full {
-  max-width: 100%;
+  @include grw-sidebar-skeleton-text(100%);
   height: 1rem;
 }