build: add ios config for phone_number

Author: deandreamatias

example/ios/Podfile

@@ -31,6 +31,7 @@ target 'Runner' do
   use_frameworks!
   use_modular_headers!
 
+  pod 'PhoneNumberKit/PhoneNumberKitCore', :git => 'https://github.com/marmelroy/PhoneNumberKit', :tag => '3.5.8'
   flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
 end