minor touchup

Author: SimaTian

src/Build.UnitTests/BackEnd/SdkResolverService_Tests.cs

@@ -5,7 +5,6 @@
 using System.Collections.Generic;
 using System.Diagnostics.Tracing;
 using System.Linq;
-using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
@@ -32,7 +31,6 @@ public class SdkResolverService_Tests
         private readonly MockLogger _logger;
         private readonly LoggingContext _loggingContext;
 
-
         public SdkResolverService_Tests()
         {
             _logger = new MockLogger();