Temp - add missing header to get build

Author: michael-hawker

common/CommunityToolkit.Labs.Core.SourceGenerators.LabsUITestMethod.Tests/LabsUITestMethodTests.cs

@@ -1,3 +1,7 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
 using CommunityToolkit.Labs.Core.SourceGenerators.LabsUITestMethod;
 using CommunityToolkit.Labs.Core.SourceGenerators.LabsUITestMethod.Diagnostics;
 using Microsoft.CodeAnalysis;