[0.81] fix clang-diagnostic-unused-function warning (#15954)

* fix clang-diagnostic-unused-function warning

* Change files

* formatting

Author: acoates-ms

change/react-native-windows-e0bd1961-aa8c-408e-8e05-11ddbf44fdc4.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "fix clang-diagnostic-unused-function warning",
+  "packageName": "react-native-windows",
+  "email": "30809111+acoates-ms@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}

vnext/Microsoft.ReactNative.Cxx/ModuleRegistration.h

@@ -70,16 +70,16 @@ struct IsReactTurboModule : std::bool_constant<ReactIsReactTurboModuleImpl(stati
   INTERNAL_REACT_RECOMPOSER_4(     \
       (__VA_ARGS__, INTERNAL_REACT_MODULE_3_ARGS, INTERNAL_REACT_MODULE_2_ARGS, INTERNAL_REACT_MODULE_1_ARG, ))
 
-#define INTERNAL_REACT_MODULE_NO_REGISTRATION_AND_PROVIDER(                                            \
-    moduleStruct, moduleName, eventEmitterName, isReactTurboModule)                                    \
-  struct moduleStruct;                                                                                 \
-                                                                                                       \
-  constexpr bool ReactIsReactTurboModuleImpl(moduleStruct *) noexcept { return isReactTurboModule; }   \
-                                                                                                       \
-  template <class TRegistry>                                                                           \
-  constexpr void GetReactModuleInfo(moduleStruct *, TRegistry &registry) noexcept {                    \
-    registry.RegisterModule(                                                                           \
-        moduleName, eventEmitterName, winrt::Microsoft::ReactNative::ReactAttributeId<__COUNTER__>{}); \
+#define INTERNAL_REACT_MODULE_NO_REGISTRATION_AND_PROVIDER(                                                           \
+    moduleStruct, moduleName, eventEmitterName, isReactTurboModule)                                                   \
+  struct moduleStruct;                                                                                                \
+                                                                                                                      \
+  [[maybe_unused]] constexpr bool ReactIsReactTurboModuleImpl(moduleStruct *) noexcept { return isReactTurboModule; } \
+                                                                                                                      \
+  template <class TRegistry>                                                                                          \
+  constexpr void GetReactModuleInfo(moduleStruct *, TRegistry &registry) noexcept {                                   \
+    registry.RegisterModule(                                                                                          \
+        moduleName, eventEmitterName, winrt::Microsoft::ReactNative::ReactAttributeId<__COUNTER__>{});                \
   }
 
 // Another version of REACT_MODULE but does not do auto registration