feat: Make sure dragged tab does not allow the title to overflow, b=no-bug, c=no-component

src/zen/drag-and-drop/ZenDragAndDrop.js

@@ -130,6 +130,7 @@
       this.#maybeCreateDragImageDot(movingTabs, wrapper);
       wrapper.style.width = tabRect.width + 'px';
       wrapper.style.height = tabRect.height * movingTabs.length + 'px';
+      wrapper.style.overflow = 'clip';
       wrapper.style.position = 'fixed';
       wrapper.style.top = '-9999px';
       periphery.appendChild(wrapper);