[SignalR] Investigate failure in TimerAwaitableTests

[pr-benchmarks]

There have been a couple failures here. Is there any hardening we can do? (cc @BrennanConroy)

Metadata

Affected Tests

Project	Type	Method
Microsoft.AspNetCore.SignalR.Client.Tests	Microsoft.AspNetCore.SignalR.Client.Tests.TimerAwaitableTests	FinalizerRunsIfTimerAwaitableReferencesObject

[BrennanConroy]

Woah fancy, how is it pinging me? Or was that you Andrew typing it through the UI?

[analogrelay]

That was me typing through the UI :)

[BrennanConroy]

I took a quick glance at this when it started flaking. I'm not 100% sure how to fix it properly, but will work on it.

[analogrelay]

Take a quick look, but don't go too deep. It's almost met the bar for unquarantining so we could unquarantine and we can try to react quicker next time it fails. Now that we have a process, we can hopefully get a little more responsive ;).

[analogrelay]

Very nice! The process at work!