Drop RCT_EXPORT_METHOD from RCTLogBox TurboModule (#57677)

Summary:
Pull Request resolved: #57677

Changelog: [Internal]

`RCTLogBox` is a TurboModule: it conforms to `NativeLogBoxSpec` and implements `getTurboModule:` returning the codegen'd `...SpecJSI`. For TurboModules, the JS->ObjC dispatch is driven by codegen (the generated spec supplies the `selector` and argument kinds, invoked at runtime via `NSMethodSignature` / `NSInvocation`), not by the `RCT_EXPORT_METHOD` macro's `__rct_export__` metadata.

The exported methods here are async-void with concrete parameter types (no generic `id` requiring `RCTConvert` coercion), so the macro is not functionally required. Convert them to plain ObjC method declarations; conformance to the codegen'd `NativeLogBoxSpec` protocol keeps compiler-enforced signature parity.

Signature-only refactor with no change to the JS-facing API. Sync methods, methods with `id` params, and `constantsToExport` are intentionally left untouched.

Reviewed By: cortinico

Differential Revision: D113579879

fbshipit-source-id: 4daee6576539c65c54394e9250e1799f611099b2

Author: christophpurrer

packages/react-native/React/CoreModules/RCTLogBox.mm

@@ -39,7 +39,7 @@ - (void)setSurfacePresenter:(id<RCTSurfacePresenterStub>)surfacePresenter
   _bridgelessSurfacePresenter = surfacePresenter;
 }
 
-RCT_EXPORT_METHOD(show)
+- (void)show
 {
   if (RCTRedBoxGetEnabled()) {
     __weak RCTLogBox *weakSelf = self;
@@ -63,7 +63,7 @@ - (void)setSurfacePresenter:(id<RCTSurfacePresenterStub>)surfacePresenter
   }
 }
 
-RCT_EXPORT_METHOD(hide)
+- (void)hide
 {
   if (RCTRedBoxGetEnabled()) {
     __weak RCTLogBox *weakSelf = self;