Fix review comments

DotNetAnalyzers#3594

Author: bjornhellander

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp11/Lightup/IImportScopeWrapperCSharp11UnitTests.cs

@@ -1,9 +1,6 @@
 // Copyright (c) Tunnel Vision Laboratories, LLC. All Rights Reserved.
 // Licensed under the MIT License. See LICENSE in the project root for license information.
 
-// Tests calls where nullability rules are not obeyed
-#pragma warning disable CS8604 // Possible null reference argument.
-
 namespace StyleCop.Analyzers.Test.Lightup
 {
     using System;
@@ -18,8 +15,8 @@ public class IImportScopeWrapperCSharp11UnitTests
         public void TestNull()
         {
             object? obj = null;
-            Assert.False(IImportScopeWrapper.IsInstance(obj));
-            var wrapper = IImportScopeWrapper.FromObject(obj);
+            Assert.False(IImportScopeWrapper.IsInstance(obj!));
+            var wrapper = IImportScopeWrapper.FromObject(obj!);
             Assert.Throws<NullReferenceException>(() => wrapper.Aliases);
         }