fix(react-native-host): handle removal of RCTArchConfiguratorProtocol.h

Author: tido64

.changeset/many-sheep-post.md

@@ -0,0 +1,5 @@
+---
+"@rnx-kit/react-native-host": patch
+---
+
+Fixed detection of unified feature flags

packages/react-native-host/cocoa/RNXFeatureMacros.h

@@ -52,9 +52,12 @@
 #define USE_UPDATE_RUNTIME_SHADOW_NODE_REFS_ON_COMMIT 1
 #endif  // __has_include(<React-RCTAppDelegate/RCTJSRuntimeConfiguratorProtocol.h>)
 
-#if !__has_include(<React/RCTCxxMethod.h>)  // >=0.87
+#if REACT_NATIVE_VERSION >= 87000
 #define RCT_REMOVE_LEGACY_ARCH 1
-#endif  // !__has_include(<React/RCTCxxMethod.h>)
+#ifndef USE_UNIFIED_FEATURE_FLAGS
+#define USE_UNIFIED_FEATURE_FLAGS 1
+#endif
+#endif  // REACT_NATIVE_VERSION >= 87000
 
 #endif  // USE_FEATURE_FLAGS