remove unsound mode web test (#118256)

dev/bots/test.dart

@@ -1236,7 +1236,6 @@ Future<void> _runWebLongRunningTests() async {
     () => _runWebDebugTest('lib/framework_stack_trace.dart'),
     () => _runWebDebugTest('lib/web_directory_loading.dart'),
     () => _runWebDebugTest('test/test.dart'),
-    () => _runWebDebugTest('lib/null_assert_main.dart', enableNullSafety: true),
     () => _runWebDebugTest('lib/null_safe_main.dart', enableNullSafety: true),
     () => _runWebDebugTest('lib/web_define_loading.dart',
       additionalArguments: <String>[

dev/integration_tests/web/lib/null_assert_main.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// ignore_for_file: enable_null_safety
-
-// @dart = 2.8
-
-import 'null_enabled_api.dart';
-
-void main() {
-  dynamic error;
-  try {
-    // Validate that a generated null assertion is thrown.
-    methodThatAcceptsNonNull(null);
-  } catch (err) {
-    error = err;
-  }
-  if (error is AssertionError) {
-    print('--- TEST SUCCEEDED ---');
-  } else {
-    print('--- TEST FAILED ---');
-  }
-}