Fixed namespace that was original an incorrect merge from v8 to v9 (#12347)

src/Umbraco.Core/Collections/StackQueue.cs

@@ -1,6 +1,4 @@
-using System.Collections.Generic;
-
-namespace Umbraco.Core.Collections
+namespace Umbraco.Cms.Core.Collections
 {
     /// <summary>
     ///     Collection that can be both a queue and a stack.

src/Umbraco.Infrastructure/Scoping/Scope.cs

@@ -11,9 +11,9 @@ using Umbraco.Cms.Core.DistributedLocking;
 using Umbraco.Cms.Core.Events;
 using Umbraco.Cms.Core.IO;
 using Umbraco.Cms.Core;
+using Umbraco.Cms.Core.Collections;
 using Umbraco.Cms.Core.Scoping;
 using Umbraco.Cms.Infrastructure.Persistence;
-using Umbraco.Core.Collections;
 using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Infrastructure.Scoping

tests/Umbraco.Tests.UnitTests/Umbraco.Core/Collections/StackQueueTests.cs

@@ -1,5 +1,5 @@
 using NUnit.Framework;
-using Umbraco.Core.Collections;
+using Umbraco.Cms.Core.Collections;
 
 namespace Umbraco.Cms.Tests.UnitTests.Umbraco.Core.Collections
 {