chore: remove React dependency

react-native-webview.podspec

   s.source       = { :git => "https://github.com/react-native-community/react-native-webview.git", :tag => "v#{s.version}" }
   s.source_files  = "apple/**/*.{h,m}"
 
-  s.dependency 'React'
   s.dependency 'React-Core'
 end