Remove uses of deprecated constants and change int.parse to int.tryParse (#19575)

* Remove uses of deprecated constants
* Change int.parse to int.tryParse where appropriate

diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index 63c8da9..2105872 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -582,7 +582,7 @@
     'framework': fs.path.basenameWithoutExtension(service['ios-framework'])
   }).toList();
   final Map<String, dynamic> jsonObject = <String, dynamic>{ 'services' : jsonServices };
-  manifest.writeAsStringSync(json.encode(jsonObject), mode: FileMode.WRITE, flush: true); // ignore: deprecated_member_use
+  manifest.writeAsStringSync(json.encode(jsonObject), mode: FileMode.write, flush: true);
 }
 
 Future<bool> upgradePbxProjWithFlutterAssets(String app, String appPath) async {