Fix build warnings

Author: sbomer

src/Tests/CollectionRuleActions.UnitTests/ActionListExecutorTests.cs

@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.AspNetCore.Http.Validation;
 using Microsoft.Diagnostics.Monitoring.TestCommon;
 using Microsoft.Diagnostics.Monitoring.TestCommon.Options;
 using Microsoft.Diagnostics.Tools.Monitor;

src/Tests/CollectionRuleActions.UnitTests/TestValidatableType.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Http.Validation;
-using Microsoft.Diagnostics.Monitoring.WebApi;
 using Microsoft.Diagnostics.Tools.Monitor.CollectionRules.Options;
 using Microsoft.Diagnostics.Tools.Monitor.CollectionRules.Options.Actions;
 
@@ -13,7 +12,7 @@ namespace Microsoft.Diagnostics.Tools.Monitor
     // in ProjectReferences. This is a workaround to force the generator running in this project to
     // generate IValidatableInfo for the referenced types. The containing class is not used otherwise.
     [ValidatableType]
-    internal class TestValidatableTypes
+    internal sealed class TestValidatableTypes
     {
         public required CollectionRuleOptions CollectionRuleOptions { get; init; }
 

src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTestsSample/Program.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.AspNetCore.Http.Validation;
-using Microsoft.Diagnostics.Tools.Monitor;
 using Microsoft.Diagnostics.Tools.Monitor.Extensibility;
 using Microsoft.Diagnostics.Tools.Monitor.Egress.FileSystem;