build: another attempt at fixing macos installation

macos/Podfile

@@ -1,8 +1,41 @@
+platform :osx, '11.0'
+
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'ephemeral', 'Flutter-Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure \"flutter pub get\" is executed first"
+  end
+
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
+  end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Flutter-Generated.xcconfig, then run \"flutter pub get\""
+end
+
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
+
+flutter_macos_podfile_setup
+
+target 'Runner' do
+  use_frameworks!
+  use_modular_headers!
+
+  flutter_install_all_macos_pods File.dirname(File.realpath(__FILE__))
+
+  target 'RunnerTests' do
+    inherit! :search_paths
+  end
+end
+
 post_install do |installer|
   installer.pods_project.targets.each do |target|
     flutter_additional_macos_build_settings(target)
+
     target.build_configurations.each do |config|
-      config.build_settings['MACOSX_DEPLOYMENT_TARGET'] = '12.0'
+      config.build_settings['MACOSX_DEPLOYMENT_TARGET'] = '11.0'
     end
   end
-end
+end