Upgrade Modal visibility to "for frameworks" (#58285)

Summary:
Pull Request resolved: #58285

Reclassifies `react/renderer/components/modal:modal` from public to "for frameworks" under the C++ stable API three-tier visibility model.

Consumers that opt into `RN_STRICT_API` now get a suppressible warning where they previously got an error pointing at the umbrella, and can acknowledge it with `RN_ALLOW_FRAMEWORKS`; without that flag the guards are inert, so no existing build changes behaviour.

Changelog: [Internal]

Reviewed By: christophpurrer

Differential Revision: D118440328

Author: j-piasecki

packages/react-native/ReactCommon/React-FabricComponents.podspec

@@ -95,12 +95,6 @@ Pod::Spec.new do |s|
       sss.header_dir           = "react/renderer/components/modal"
     end
 
-    ss.subspec "modalUmbrella" do |sss|
-      sss.source_files         = "react/renderer/components/modal/React/*.h"
-      sss.header_dir           = ""
-      sss.header_mappings_dir  = "react/renderer/components/modal"
-    end
-
     ss.subspec "safeareaview" do |sss|
       sss.source_files         = podspec_sources("react/renderer/components/safeareaview/**/*.{m,mm,cpp,h}", "react/renderer/components/safeareaview/**/*.h")
       # Exclude tests to avoid conflicts with the react-native-safe-area-context package

packages/react-native/ReactCommon/react/renderer/components/modal/ModalHostViewComponentDescriptor.h

@@ -7,7 +7,7 @@
 
 #pragma once
 
-#include <react/cxxstableapi/UmbrellaGuard.h>
+#include <react/cxxstableapi/FrameworksGuard.h>
 
 #include <glog/logging.h>
 #include <react/renderer/components/modal/ModalHostViewShadowNode.h>

packages/react-native/ReactCommon/react/renderer/components/modal/ModalHostViewShadowNode.h

@@ -7,7 +7,7 @@
 
 #pragma once
 
-#include <react/cxxstableapi/UmbrellaGuard.h>
+#include <react/cxxstableapi/FrameworksGuard.h>
 
 #include <react/renderer/components/FBReactNativeSpec/EventEmitters.h>
 #include <react/renderer/components/FBReactNativeSpec/Props.h>

packages/react-native/ReactCommon/react/renderer/components/modal/ModalHostViewState.h

@@ -7,7 +7,7 @@
 
 #pragma once
 
-#include <react/cxxstableapi/UmbrellaGuard.h>
+#include <react/cxxstableapi/FrameworksGuard.h>
 
 #include <react/renderer/core/graphicsConversions.h>
 #include <react/renderer/graphics/Float.h>

packages/react-native/ReactCommon/react/renderer/components/modal/ModalHostViewUtils.h

@@ -7,7 +7,7 @@
 
 #pragma once
 
-#include <react/cxxstableapi/UmbrellaGuard.h>
+#include <react/cxxstableapi/FrameworksGuard.h>
 
 #include <react/renderer/graphics/Size.h>
 

packages/react-native/ReactCommon/react/renderer/components/modal/React/Modal.h

@@ -357,12 +357,6 @@ const PodspecExceptions /*: {[key: string]: PodSpecConfiguration} */ = {
             headerDir: 'react/renderer/components/modal',
           },
 
-          {
-            name: 'modalUmbrella',
-            headerPatterns: ['react/renderer/components/modal/React/*.h'],
-            headerDir: 'React',
-          },
-
           {
             name: 'safeareaview',
             headerPatterns: ['react/renderer/components/safeareaview/**/*.h'],