`AddAuthorization()` / `AddTestAuthorization()` doesn't work with shallow rendering

[aayjaychan]

Describe the bug

When testing a component with authentication, using shallow rendering to replace all child components throws ComponentNotFoundException.

Example:
Foo.razor:

@using System.Threading.Tasks;
@using Microsoft.AspNetCore.Components.Authorization

<div>
</div>

@code
{
    [CascadingParameter]
    public Task<AuthenticationState> Auth { get; set; } = null!;
}

Test:

using Bunit;
using NUnit.Framework;

public sealed class FooTests
{
    [Test]
    public void TestFoo()
    {
        using BunitContext testContext = new();

        testContext.AddAuthorization();
        testContext.ComponentFactories
            .AddStub(componentType => componentType != typeof(Foo));
        testContext.Render<Foo>();
    }
}

Results in this output:

Bunit.Rendering.ComponentNotFoundException : A component of type ContainerFragment was not found in the render tree.
   at Bunit.Rendering.BunitRenderer.FindComponent[TComponent](IRenderedComponent`1 parentComponent) in /_/src/bunit/Rendering/BunitRenderer.cs:line 216
   at Bunit.BunitContext.RenderInsideRenderTree(RenderFragment renderFragment) in /_/src/bunit/BunitContext.cs:line 226
   at Bunit.BunitContext.RenderInsideRenderTree[TComponent](RenderFragment renderFragment) in /_/src/bunit/BunitContext.cs:line 208
   at Bunit.BunitContext.Render[TComponent](RenderFragment renderFragment) in /_/src/bunit/BunitContext.cs:line 163
   at Bunit.BunitContext.Render[TComponent](Action`1 parameterBuilder) in /_/src/bunit/BunitContext.cs:line 149
   at FooTests.TestFoo() in /mnt/data/Projects/Tests/FooTests.cs:line 15
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)

Expected behavior:

Services and components added by AddTestAuthorization() are not affected by AddStub().

Version info:

• bUnit version: 1.40.0, 2.0.64-preview
• .NET Runtime and Blazor version: 8.0.20