Fix macOS SPM build: conditionally exclude iOS/macOS switch files

IOSSwitchShadowNode.mm imports UIKit which doesn't exist on macOS.
Use #if os(macOS) to exclude the iOS variant and include the macOS
variant (and vice versa on iOS), matching the existing pattern for
view platform sources.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Saadnajmi

packages/react-native/Package.swift

@@ -385,9 +385,11 @@ let reactCore = RNTarget(
 #if os(macOS)
 let reactFabricViewPlatformSources = ["components/view/platform/macos"]
 let reactFabricViewPlatformExcludes = ["components/view/platform/cxx"]
+let reactFabricComponentsSwitchExcludes = ["components/switch/iosswitch/react/renderer/components/switch/IOSSwitchShadowNode.mm"]
 #else
 let reactFabricViewPlatformExcludes = ["components/view/platform/macos"]
 let reactFabricViewPlatformSources = ["components/view/platform/cxx"]
+let reactFabricComponentsSwitchExcludes = ["components/switch/iosswitch/react/renderer/components/switch/MacOSSwitchShadowNode.mm"]
 #endif
 // macOS]
 let reactFabric = RNTarget(
@@ -446,7 +448,7 @@ let reactFabricComponents = RNTarget(
     "components/view/platform/android",
     "components/view/platform/windows",
     "components/view/platform/macos",
-    "components/switch/iosswitch/react/renderer/components/switch/MacOSSwitchShadowNode.mm",
+    // "components/switch/iosswitch/.../MacOSSwitchShadowNode.mm" or "IOSSwitchShadowNode.mm" — [macOS] see reactFabricComponentsSwitchExcludes
     "components/textinput/platform/android",
     "components/text/platform/android",
     "components/textinput/platform/macos",
@@ -457,7 +459,7 @@ let reactFabricComponents = RNTarget(
     "textlayoutmanager/platform/windows",
     "textlayoutmanager/platform/macos",
     "conponents/rncore", // this was the old folder where RN Core Components were generated. If you ran codegen in the past, you might have some files in it that might make the build fail.
-  ],
+  ] + reactFabricComponentsSwitchExcludes, // [macOS]
   dependencies: [.reactNativeDependencies, .reactCore, .reactJsiExecutor, .reactTurboModuleCore, .jsi, .logger, .reactDebug, .reactFeatureFlags, .reactUtils, .reactRuntimeScheduler, .reactCxxReact, .yoga, .reactRendererDebug, .reactGraphics, .reactFabric, .reactTurboModuleBridging],
   sources: ["components/inputaccessory", "components/modal", "components/safeareaview", "components/text", "components/text/platform/cxx", "components/textinput", "components/textinput/platform/ios/", "components/unimplementedview", "components/virtualview", "textlayoutmanager", "textlayoutmanager/platform/ios", "components/switch/iosswitch"]
 )