Update System.Threading.Tasks.Extensions to 4.5.3 (#37316)

eng/Versions.props

@@ -187,7 +187,7 @@
     <SystemThreadingTasksDataflowVersion>4.5.24</SystemThreadingTasksDataflowVersion>
     <!-- We need System.ValueTuple assembly version at least 4.0.3.0 on net47 to make F5 work against Dev15 - see https://github.com/dotnet/roslyn/issues/29705 -->
     <SystemValueTupleVersion>4.5.0</SystemValueTupleVersion>
-    <SystemThreadingTasksExtensionsVersion>4.5.2</SystemThreadingTasksExtensionsVersion>
+    <SystemThreadingTasksExtensionsVersion>4.5.3</SystemThreadingTasksExtensionsVersion>
     <SQLitePCLRawbundle_greenVersion>1.1.2</SQLitePCLRawbundle_greenVersion>
     <UIAComWrapperVersion>1.1.0.14</UIAComWrapperVersion>
     <MicrosoftVSSDKBuildToolsVersion>15.8.68-develop-g109a00ff</MicrosoftVSSDKBuildToolsVersion>