fix: restore original Podfile configuration

Reverts unintended changes to Podfile that were accidentally included in the previous commit

Author: ened

example/ios/Podfile

@@ -1,5 +1,5 @@
 # Uncomment this line to define a global platform for your project
-# platform :ios, '12.0'
+platform :ios, '14.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
@@ -29,6 +29,7 @@ flutter_ios_podfile_setup
 
 target 'Runner' do
   use_frameworks!
+  use_modular_headers!
 
   flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
   target 'RunnerTests' do