Remove incorrect text about web renderer default (#85214)

packages/flutter_tools/lib/src/commands/test.dart

@@ -167,7 +167,7 @@ class TestCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts {
         defaultsTo: 'tester',
         help: 'Selects the test backend.',
         allowedHelp: <String, String>{
-          'tester': 'Run tests using the default VM-based test environment.',
+          'tester': 'Run tests using the VM-based test environment.',
           'chrome': '(deprecated) Run tests using the Google Chrome web browser. '
                     'This value is intended for testing the Flutter framework '
                     'itself and may be removed at any time.',

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -563,7 +563,7 @@ abstract class FlutterCommand extends Command<void> {
       allowed: <String>['auto', 'canvaskit', 'html'],
       help: 'The renderer implementation to use when building for the web.',
       allowedHelp: <String, String>{
-        'html': 'Always use the HTML renderer. This renderer uses a combination of HTML, CSS, SVG, 2D Canvas, and WebGL. This is the default.',
+        'html': 'Always use the HTML renderer. This renderer uses a combination of HTML, CSS, SVG, 2D Canvas, and WebGL.',
         'canvaskit': 'Always use the CanvasKit renderer. This renderer uses WebGL and WebAssembly to render graphics.',
         'auto': 'Use the HTML renderer on mobile devices, and CanvasKit on desktop devices.',
       }

packages/flutter_tools/test/general.shard/args_test.dart

@@ -86,6 +86,16 @@ void verifyOptions(String command, Iterable<Option> options) {
     expect(option.help, isNot(matches(_questionablePatterns)), reason: '${_header}Help for $target--${option.name}" may have a typo. (If it does not you may have to update args_test.dart, sorry. Search for "_questionablePatterns")');
     if (option.defaultsTo != null) {
       expect(option.help, isNot(contains('Default')), reason: '${_header}Help for $target--${option.name}" mentions the default value but that is redundant with the defaultsTo option which is also specified (and preferred).');
+
+      if (option.allowedHelp != null) {
+        for (final String allowedValue in option.allowedHelp.keys) {
+          expect(
+            option.allowedHelp[allowedValue],
+            isNot(anyOf(contains('default'), contains('Default'))),
+            reason: '${_header}Help for $target--${option.name} $allowedValue" mentions the default value but that is redundant with the defaultsTo option which is also specified (and preferred).',
+          );
+        }
+      }
     }
     expect(option.help, isNot(matches(_bannedArgumentReferencePatterns)), reason: '${_header}Help for $target--${option.name}" contains the string "--" in an unexpected way. If it\'s trying to mention another argument, it should be quoted, as in "--foo".');
     for (final String line in option.help.split('\n')) {