Do not add checkbox padding to the left of menu items if no item actually needs it

[bdach]

RFC. As per https://discord.com/channels/188630481301012481/188630652340404224/1291346164976980009.

2024-10-03.15-34-24.mp4

The diff is extremely dumb (linq in update method) but I tried a few smarter methods and they're either not fully correct or don't work. Primary problem is that menu items are mutable externally and there's no hook provided by the framework to know that items changed. One could probably be made but I'd prefer that this change be examined visually first before I engage in too much ceremony and start changing framework around. Measured overhead in profiling is ~16us per call.

[peppy]

The unfortunate truth is that this allocates out the rear:

I'm fine with a non-LINQ version though:

diff --git a/osu.Game/Graphics/UserInterface/OsuMenu.cs b/osu.Game/Graphics/UserInterface/OsuMenu.cs
index 719100e138..6e7dad2b5f 100644
--- a/osu.Game/Graphics/UserInterface/OsuMenu.cs
+++ b/osu.Game/Graphics/UserInterface/OsuMenu.cs
@@ -3,7 +3,6 @@
 
 #nullable disable
 
-using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Sample;
@@ -47,10 +46,19 @@ protected override void Update()
         {
             base.Update();
 
-            bool showCheckboxes = Items.Any(i => i is StatefulMenuItem);
+            bool showCheckboxes = false;
 
-            foreach (var drawableItem in ItemsContainer.OfType<DrawableOsuMenuItem>())
-                drawableItem.ShowCheckbox.Value = showCheckboxes;
+            foreach (var drawableItem in ItemsContainer)
+            {
+                if (drawableItem.Item is StatefulMenuItem)
+                    showCheckboxes = true;
+            }
+
+            foreach (var drawableItem in ItemsContainer)
+            {
+                if (drawableItem is DrawableOsuMenuItem osuItem)
+                    osuItem.ShowCheckbox.Value = showCheckboxes;
+            }
         }
 
         protected override void AnimateOpen()