Merge 30dd1e79df into 033a0540f7

At this time, only the **Hotkey Settings** dialog will use vertical
tabs. This dialog happens to feature many tabs that, when horizontal
tabs are used, require horizontal scroll. Also, with these many tabs,
it can make good use of the vertical space that the vertical tabs
require.

| Before | After |
| ------ | ----- |
| <img width="918" height="679" alt="[Dolphin Emulator] Hotkey Settings dialog" title="[Dolphin Emulator] Hotkey Settings dialog" src="https://github.com/user-attachments/assets/7c9d9964-f36b-4872-ab52-6ebbe974a8ca" /> | <img width="1041" height="653" alt="[Dolphin Emulator] Hotkey Settings dialog with vertical tabs" title="[Dolphin Emulator] Hotkey Settings dialog with vertical tabs" src="https://github.com/user-attachments/assets/c6d875f9-f52d-4564-9d68-0555521a77fa" /> |

Source/Core/DolphinQt/QtUtils/VerticalTabsTabWidget.cpp

@@ -32,16 +32,16 @@ protected:
     for (int i{0}; i < tab_count; ++i)
     {
       if (i != current_tab_index)
-        PaintTab(painter, i);
+        paintTab(painter, i);
     }
 
     // Current tab is painted last as, depending on the [system] style, it is possible that the
     // decoration is required to occlude the adjacent tab underneath.
-    PaintTab(painter, current_tab_index);
+    paintTab(painter, current_tab_index);
   }
 
 private:
-  void PaintTab(QStylePainter& painter, const int tab_index)
+  void paintTab(QStylePainter& painter, const int tab_index)
   {
     painter.save();