[bare-expo][ios] remove xcode 15 workarounds (#25599)

# Why

as mentioned earlier, we should not commit the workarounds to git and make it compatible with xcode 14.

# How

- remove `_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION` workaround since now we have newer boost library
- remove `-ld_classic` to be compatible with xcode 14

ios/Podfile

@@ -95,17 +95,8 @@ abstract_target 'Expo Go' do
         end
       end
 
-      # Xcode 15 build error workaround. Remove after updating RN
-      target_installation_result.native_target.build_configurations.each do |config|
-        # unary_function and binary_function are no longer provided in C++17 and newer standard modes as part of Xcode 15. They can be re-enabled with setting _LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION
-        # Ref: https://developer.apple.com/documentation/xcode-release-notes/xcode-15-release-notes#Deprecations
-        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= ['$(inherited)']
-        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] << '"_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION" '
-      end
-
       target_installation_result.native_target.build_configurations.each do |config|
         config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '13.4'
-
       end
 
       if pod_name == 'Branch'