Removed obsolete constants

Author: camrein

src/ParallelHelper/Analyzer/Smells/AwaitSynchronousTaskCompletionAnalyzer.cs

@@ -35,9 +35,6 @@ public class AwaitSynchronousTaskCompletionAnalyzer : DiagnosticAnalyzer {
       isEnabledByDefault: true, description: Description, helpLinkUri: HelpLinkFactory.CreateUri(DiagnosticId)
     );
 
-    private const string TaskType = "System.Threading.Tasks.Task";
-    private const string CompletedTaskProperty = "CompletedTask";
-
     public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
 
     public override void Initialize(AnalysisContext context) {