Null safety cleanup in test runner code

Author: nshahan

frontend_server_common/lib/src/devfs.dart

@@ -29,7 +29,6 @@ class WebDevFS {
     required this.projectDirectory,
     required this.packageUriMapper,
     required this.index,
-    this.soundNullSafety = true,
     this.urlTunneler,
     required this.sdkLayout,
     required this.compilerOptions,
@@ -46,9 +45,6 @@ class WebDevFS {
   List<Uri> sources = <Uri>[];
   DateTime? lastCompiled;
 
-  @Deprecated('Only sound null safety is supported as of Dart 3.0')
-  final bool soundNullSafety;
-
   final TestSdkLayout sdkLayout;
   final CompilerOptions compilerOptions;
 

test_common/lib/test_sdk_configuration.dart

@@ -14,11 +14,8 @@ import 'package:test_common/test_sdk_layout.dart';
 /// Implementation for SDK configuration for tests that can generate
 /// missing assets.
 ///
-///  - Generate SDK js, source map, and full dill (normally included in flutter
-///    SDK or produced by build).
-///
-/// TODO(annagrin): update to only generating missing sound artifacts
-/// for frontend server after we have no uses of weak null safety.
+///  - Generate SDK js, source map (normally included in flutter SDK
+///    or produced by build).
 class TestSdkConfigurationProvider extends SdkConfigurationProvider {
   final _logger = Logger('TestSdkConfigurationProvider');