fix(podspec): comment out duplicate scrollview subspec in React-FabricComponents

[Saadnajmi]

Summary

The scrollview subspec is declared in BOTH React-Fabric.podspec and React-FabricComponents.podspec, with overlapping source_files:

• React-Fabric.podspec → react/renderer/components/scrollview/**/*.{m,mm,cpp,h} (recursive)
• React-FabricComponents.podspec → react/renderer/components/scrollview/*.{m,mm,cpp,h} + scrollview/platform/cxx/**/* (non-recursive + platform/cxx)

Both globs include the same top-level files (ScrollViewShadowNode.cpp, BaseScrollViewProps.cpp, ScrollEvent.cpp, etc.). After pod install, those source files end up in both the React-Fabric and React-FabricComponents Pods targets.

What breaks

• Consumers that link both libraries (e.g. via -all_load) hit duplicate symbol errors at link time.
• Consumers that deduplicate by hand by dropping scrollview sources from one target break differently: React-Fabric's mounting/internal/CullingContext.cpp references ScrollViewShadowNode, so if the dedup drops it from React-Fabric, link fails with Undefined symbols: ScrollViewShadowNode.

Fix

Comment out (rather than delete, per the macOS diffs-with-upstream guide) the scrollview subspec in React-FabricComponents.podspec, wrapped in # [macOS / # macOS] diff tags with an inline explanation. The recursive glob in React-Fabric.podspec's scrollview subspec already covers everything FabricComponents was listing.

Test plan

• pod install succeeded against this branch (RCT_NEW_ARCH_ENABLED=0 in packages/rn-tester/).
• Generated Pods.xcodeproj:
  • React-Fabric-macOS target's Sources phase contains ScrollViewShadowNode.cpp, BaseScrollViewProps.cpp, ScrollEvent.cpp, ScrollViewEventEmitter.cpp, ScrollViewState.cpp ✓
  • React-FabricComponents-macOS target's Sources phase does NOT contain those files ✓
• Build verification on RNTester (CI will do this)

Discovered while integrating react-native-macos v0.81.6 into a monorepo that links both libReact-Fabric-macOS.a and libReact-FabricComponents-macOS.a via -all_load.