Attempt to fix test flickers and remove/silence teardown failures that pollute the log.

[MayaKirova]

Closes #249

[Copilot]

Pull request overview

This PR targets flaky Playwright-based integration tests in the Lite test bed by making property-setting assertions wait for an actual Blazor render instead of relying on tiny delays, and by reducing teardown noise from SignalR disposal during shutdown (Issue #249).

Changes:

• Replace StateHasChanged() + Task.Delay(1) in the property test loop with a render-awaiting helper (WaitForRenderAsync) to reduce timing flicker.
• Update Playwright teardown to navigate away/close the page before disposing the host, aiming to drop SignalR connections cleanly.
• Filter specific ASP.NET Core SignalR/connection manager log categories down to Critical during tests to reduce teardown log pollution.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
tests/IgniteUI.Blazor.Lite.TestBed/Components/Pages/Home.razor	Adds a “wait for next render” mechanism and uses it in property testing to reduce timing-related mismatches.
tests/IgniteUI.Blazor.Lite.IntegrationTests/Infrastructure/BlazorPageTest.cs	Improves teardown order by navigating away and closing the Playwright page before disposing the host/context.
tests/IgniteUI.Blazor.Lite.IntegrationTests/Infrastructure/BlazorApplicationFactory.cs	Adds logging filters to suppress known teardown-time SignalR disposal noise.

Comments suppressed due to low confidence (1)

tests/IgniteUI.Blazor.Lite.TestBed/Components/Pages/Home.razor:281

• WaitForRenderAsync overwrites pendingRender on every call. If a previous render is still in-flight (or times out) and a subsequent property set happens before it completes, the completion of the earlier render can incorrectly release the newer waiter, reintroducing the exact kind of flicker this is meant to fix. Reuse a single TCS while a render is pending (and only create a new one when none is pending).

        // new TaskCompletionSource that will wait for render
        var renderTcs = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
        this.pendingRender = renderTcs;

        // trigger StateHasChanged to request a render.