OverlayArenaSystem: S2's delegate is a task delegate

The vtable its ctor installs (0x710251A960) is a
Delegate1R<void*, bool>, and the callback returns bool.

(AI assisted using Claude Opus 5.5)

src/KingSystem/System/OverlayArenaSystemS2.h

@@ -23,7 +23,7 @@ public:
 
 private:
     u32 _0 = 0;
-    sead::Delegate1<OverlayArenaSystemS2, void*> mDelegate;
+    sead::Delegate1R<OverlayArenaSystemS2, void*, bool> mDelegate;
     u32 _28 = 1;
     void* _30 = nullptr;
     void* _38 = nullptr;