[test-quarantine] Quarantine ServerRoutingTest and ServerVirtualizationTest flaky tests (#65964)

* Quarantine ServerRoutingTest and ServerVirtualizationTest flaky tests

ServerRoutingTest.NavigationLock_OverlappingNavigationsCancelExistingNavigations_HistoryNavigation
failed 18 times in the components-e2e pipeline over the last 30 days.
Associated issue: #65960

ServerVirtualizationTest.CanRenderHtmlTable and CanElevateEffectiveMaxItemCount_WhenOverscanExceedsMax
failed 2 and 4 times respectively in the components-e2e pipeline.
Associated issue: #65961

The xUnit QuarantinedTest attribute is not automatically inherited by server-side
test subclasses. Adding explicit virtual overrides to apply the quarantine
attribute to the server execution variants.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add missing using directive for InternalTesting

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: William Godbe <wigodbe@microsoft.com>

Author: 3 people

src/Components/test/E2ETest/ServerExecutionTests/TestSubclasses.cs

@@ -5,6 +5,7 @@
 using Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures;
 using Microsoft.AspNetCore.Components.E2ETest.Tests;
 using Microsoft.AspNetCore.E2ETesting;
+using Microsoft.AspNetCore.InternalTesting;
 using Xunit.Abstractions;
 
 namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests;
@@ -42,6 +43,10 @@ public ServerRoutingTest(BrowserFixture browserFixture, ToggleExecutionModeServe
         : base(browserFixture, serverFixture.WithServerExecution(), output)
     {
     }
+
+    [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/61080")]
+    public override void NavigationLock_OverlappingNavigationsCancelExistingNavigations_HistoryNavigation()
+        => base.NavigationLock_OverlappingNavigationsCancelExistingNavigations_HistoryNavigation();
 }
 
 public class ServerCascadingValueTest : CascadingValueTest
@@ -90,6 +95,14 @@ public ServerVirtualizationTest(BrowserFixture browserFixture, ToggleExecutionMo
         : base(browserFixture, serverFixture.WithServerExecution(), output)
     {
     }
+
+    [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/65852")]
+    public override void CanRenderHtmlTable()
+        => base.CanRenderHtmlTable();
+
+    [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/65852")]
+    public override void CanElevateEffectiveMaxItemCount_WhenOverscanExceedsMax()
+        => base.CanElevateEffectiveMaxItemCount_WhenOverscanExceedsMax();
 }
 
 public class ServerDynamicComponentRenderingTest : DynamicComponentRenderingTest

src/Components/test/E2ETest/Tests/RoutingTest.cs

@@ -971,7 +971,7 @@ public void NavigationLock_OverlappingNavigationsCancelExistingNavigations_PushS
 
     [Fact]
     [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/61080")]
-    public void NavigationLock_OverlappingNavigationsCancelExistingNavigations_HistoryNavigation()
+    public virtual void NavigationLock_OverlappingNavigationsCancelExistingNavigations_HistoryNavigation()
     {
         SetUrlViaPushState("/");
 

src/Components/test/E2ETest/Tests/VirtualizationTest.cs

@@ -252,7 +252,7 @@ public async Task ToleratesIncorrectItemSize()
 
     [Fact]
     [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/65852")]
-    public void CanRenderHtmlTable()
+    public virtual void CanRenderHtmlTable()
     {
         Browser.MountTestComponent<VirtualizationTable>();
         var expectedInitialSpacerStyle = "height: 0px; flex-shrink: 0;";
@@ -612,7 +612,7 @@ public void EmptyContentRendered_Async()
 
     [Fact]
     [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/65852")]
-    public void CanElevateEffectiveMaxItemCount_WhenOverscanExceedsMax()
+    public virtual void CanElevateEffectiveMaxItemCount_WhenOverscanExceedsMax()
     {
         Browser.MountTestComponent<VirtualizationLargeOverscan>();
         var container = Browser.Exists(By.Id("virtualize-large-overscan"));