Fix the Catalyst build after 272187@main

https://bugs.webkit.org/show_bug.cgi?id=266557
rdar://119784872

Unreviewed build fix.

* Source/WebKit/UIProcess/ios/WKContentViewInteraction.mm:
(-[WKContentView _requiresLegacyTextInputTraits]):
Make the return type explicit because sometimes the compiler is picky about BOOL vs. bool.

Canonical link: https://commits.webkit.org/272193@main

Source/WebKit/UIProcess/ios/WKContentViewInteraction.mm

@@ -6691,7 +6691,7 @@ - (BOOL)_requiresLegacyTextInputTraits
     if (_cachedRequiresLegacyTextInputTraits.has_value())
         return *_cachedRequiresLegacyTextInputTraits;
 
-    _cachedRequiresLegacyTextInputTraits = [&] {
+    _cachedRequiresLegacyTextInputTraits = [&]() -> BOOL {
         if (!self.shouldUseAsyncInteractions)
             return YES;