Since version 106 a v (as in down arrow) has appeared on the tab bar as can be seen at the right-hand end of this example.
How do I remove it? Dragging off the tab bar does not work. Why do I want it gone? Simple I have no need for it. In general I do not have enough tabs open in a particualr window to warrant need to have a list. On the occasions when I do have more tabs than can be immediately displayed on the tab bar I scroll left/right with a ouse gesture. This v is intrusive and reduces the real estate on the bar for more important things like another tab.