Update SDK to 1.6.0 (temporalio#98)

Author: cretz

Directory.Build.props

@@ -19,10 +19,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Temporalio" Version="1.4.0" />
-    <PackageReference Include="Temporalio.Extensions.DiagnosticSource" Version="1.4.0" />
-    <PackageReference Include="Temporalio.Extensions.Hosting" Version="1.4.0" />
-    <PackageReference Include="Temporalio.Extensions.OpenTelemetry" Version="1.4.0" />
+    <PackageReference Include="Temporalio" Version="1.6.0" />
+    <PackageReference Include="Temporalio.Extensions.DiagnosticSource" Version="1.6.0" />
+    <PackageReference Include="Temporalio.Extensions.Hosting" Version="1.6.0" />
+    <PackageReference Include="Temporalio.Extensions.OpenTelemetry" Version="1.6.0" />
     <!--
     Can also reference the SDK downloaded to a local directory:
     <ProjectReference Include="$(MSBuildThisFileDirectory)..\temporal-sdk-dotnet\src\Temporalio\Temporalio.csproj" />

src/SafeMessageHandlers/ClusterManagerWorkflow.workflow.cs

@@ -172,7 +172,7 @@ await Workflow.ExecuteActivityAsync(
 
     private bool ShouldContinueAsNew =>
         // Don't continue as new while update running
-        nodesLock.CurrentCount > 0 &&
+        Workflow.AllHandlersFinished &&
         // Continue if suggested or, for ease of testing, max history reached
         (Workflow.ContinueAsNewSuggested || Workflow.CurrentHistoryLength > maxHistoryLength);