Fix new analyzer warnings

Author: stuartmorgan-g

packages/flutter_migrate/test/base/logger_test.dart

@@ -45,7 +45,7 @@ void main() {
     final WindowsStdoutLogger logger = WindowsStdoutLogger(
       outputPreferences: OutputPreferences.test(),
       stdio: stdio,
-      terminal: Terminal.test(supportsColor: false, supportsEmoji: false),
+      terminal: Terminal.test(),
     );
 
     logger.printStatus('🔥🖼️✗✓🔨💪✏️');

packages/pigeon/lib/cpp_generator.dart

@@ -773,7 +773,7 @@ const flutter::StandardMessageCodec& ${api.name}::GetCodec() {
       final Iterable<String> argNames =
           indexMap(func.arguments, _getSafeArgumentName);
       sendArgument =
-          'flutter::EncodableList { ${(argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)')).join(', ')} }';
+          'flutter::EncodableList { ${argNames.map((String arg) => 'flutter::CustomEncodableValue($arg)').join(', ')} }';
       final String argsSignature =
           map2(argTypes, argNames, (String x, String y) => '$x $y').join(', ');
       indent