Fix race condition when caching for a type of QueryParameterValueSupplier

[mayuki]

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Description

Fixes #40595

QueryParameterValueSupplier.ForType static method caches a QueryParameterValueSupplier in the Dictionary for each type.

The Dictionary for this cache is not locked and will be broken if multiple requests hit it on the first access.
This can also happen under heavy workloads or in cases such as health checks from load balancers at start-up.

It can be reproduced randomly by starting the Blazor Server with the following code running in a separate process.

var httpClient = new HttpClient();
var tasks = Enumerable.Range(0, 10).Select(async x =>
{
    while (true)
    {
        try
        {
            await httpClient.GetStringAsync("http://localhost:5167/");
        }
        catch {}
    }
})
.ToArray();
await Task.WhenAll(tasks);

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Collections.Generic.Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
   at Microsoft.AspNetCore.Components.Routing.QueryParameterValueSupplier.ForType(Type componentType) in C:\Users\UserName\source\repos\GitHub\mayuki-aspnetcore\src\Components\Components\src\Routing\QueryParameterValueSupplier.cs:line 35
   at Microsoft.AspNetCore.Components.RouteView.RenderPageWithParameters(RenderTreeBuilder builder) in C:\Users\UserName\source\repos\GitHub\mayuki-aspnetcore\src\Components\Components\src\RouteView.cs:line 95
   at Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder.AddContent(Int32 sequence, RenderFragment fragment) in C:\Users\UserName\source\repos\GitHub\mayuki-aspnetcore\src\Components\Components\src\Rendering\RenderTreeBuilder.cs:line 113
   at BlazorApp4.Shared.MainLayout.BuildRenderTree(RenderTreeBuilder __builder) in C:\Users\UserName\source\repos\Sandbox\BlazorApp4\BlazorApp4\Shared\MainLayout.razor:line 16
   at Microsoft.AspNetCore.Components.ComponentBase.<.ctor>b__6_0(RenderTreeBuilder builder) in C:\Users\UserName\source\repos\GitHub\mayuki-aspnetcore\src\Components\Components\src\ComponentBase.cs:line 40
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException) in C:\Users\UserName\source\repos\GitHub\mayuki-aspnetcore\src\Components\Components\src\Rendering\ComponentState.cs:line 69

[mkArtakMSFT]

Thanks for your contribution, @mayuki!

@javiercn feel free to merge if you have no further feedback.

[javiercn]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/aspnetcore/actions/runs/1968359849

[github-actions]

@javiercn an error occurred while backporting to release/6.0, please check the run log for details!

Error: @javiercn is not a repo collaborator, backporting is not allowed.

[javiercn]

@Pilchie not sure why my permissions don't work?

[mkArtakMSFT]

@wtgodbe do you know what permissions are needed for the backport bot to succeed?
I believe @javiercn is a collaborator, how otherwise he would merge this PR?

Error: @javiercn is not a repo collaborator, backporting is not allowed.

[wtgodbe]

@javiercn You have to flip the visibility if your dotnet github org membership to public here: https://github.com/orgs/dotnet/people

[javiercn]

@wtgodbe thanks