Potential fix for pull request finding 'Useless assignment to local variable'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

Author: YunchuWang

test/Worker/Grpc.Tests/LoggingCategoryTests.cs

@@ -180,7 +180,7 @@ public void GrpcDurableTaskWorker_EmitsToBothCategories_WhenLegacyCategoriesEnab
         var services = new ServiceCollection().BuildServiceProvider();
 
         // Act - Create worker which will create the logger internally
-        var worker = new GrpcDurableTaskWorker(
+        _ = new GrpcDurableTaskWorker(
             name: "Test",
             factory: factoryMock.Object,
             grpcOptions: new OptionsMonitorStub<GrpcDurableTaskWorkerOptions>(grpcOptions),