Avoid repainting new tab button for native tab bar

macos/Sources/Features/Terminal/TerminalWindow.swift

@@ -16,13 +16,19 @@ class TerminalWindow: NSWindow {
         }
         
         super.becomeKey()
+
+        if titlebarTabs {
             updateNewTabButtonOpacity()
         }
+    }
 
     override func resignKey() {
         super.resignKey()
+
+        if titlebarTabs {
             updateNewTabButtonOpacity()
         }
+    }
 
     // MARK: - Titlebar Tabs
     
@@ -211,6 +217,8 @@ class TerminalWindow: NSWindow {
     override func update() {
         super.update()
 
+        guard titlebarTabs else { return }
+
         // This is called when we open, close, switch, and reorder tabs, at which point we determine if the
         // first tab in the tab bar is selected. If it is, we make the `windowButtonsBackdrop` color the same
         // as that of the active tab (i.e. the titlebar's background color), otherwise we make it the same