fix: FF scroll bar width (ElemeFE#18091)

Author: iamkun

packages/theme-chalk/src/scrollbar.scss

@@ -19,6 +19,7 @@
     height: 100%;
 
     @include m(hidden-default) {
+      scrollbar-width: none;
       &::-webkit-scrollbar {
         width: 0;
         height: 0;