Fix chapter scroller issue on Chrome 126 on OS X

On some machines setting `scrollLeft` does not work on containers with
no pointer-events. Switching overflow to scroll works around the
problem. Use CSS to prevent scroll bars showing up.

REDMINE-20780

entry_types/scrolled/package/src/widgets/defaultNavigation/Scroller.module.css

@@ -2,8 +2,9 @@
 
 @media screen and breakpoint-md {
   .scroller {
-    overflow: hidden;
+    overflow: scroll;
     scroll-behavior: smooth;
+    scrollbar-width: none;
 
     /* Prevent clipping chapter tooltips vertically. */
     padding-bottom: 90vh;
@@ -14,6 +15,10 @@
     width: 58%;
   }
 
+  .scroller::-webkit-scrollbar {
+    display: none;
+  }
+
   .scroller > * {
     pointer-events: auto;
   }