FIX: fix dragging in horizontal overflow component (#20018)

app/assets/javascripts/discourse/app/components/horizontal-overflow-nav.js

@@ -78,19 +78,20 @@ export default class HorizontalOverflowNav extends Component {
     const mouseDragScroll = function (e) {
       let mouseChange = e.clientX - position.x;
       navPills.scrollLeft = position.left - mouseChange;
-
-      navPills.querySelectorAll("a").forEach((a) => {
-        a.style.cursor = "grabbing";
-      });
     };
 
+    navPills.querySelectorAll("a").forEach((a) => {
+      a.style.cursor = "grabbing";
+    });
+
     const removeDragScroll = function () {
+      document.removeEventListener("mousemove", mouseDragScroll);
       navPills.querySelectorAll("a").forEach((a) => {
         a.style.cursor = "pointer";
       });
     };
 
-    document.addEventListener("mousemove", mouseDragScroll, { once: true });
+    document.addEventListener("mousemove", mouseDragScroll);
     document.addEventListener("mouseup", removeDragScroll, { once: true });
   }