.NET Client - re-using default handlers causes `ClientFactory.Build()` to fail after any request has been issued

[caleblloyd]

The static handlers here are causing any call to ClientFactory.Build() to fail after a request on a previous built client has been issued:

source-generator/stage/dotnet/dotnet-sdk/src/Client/ClientFactory.cs

Lines 20 to 26 in fcf6805

	private static readonly Lazy<List<DelegatingHandler>> s_handlers =
	new(() =>
	[
	new APIVersionHandler(),
	new UserAgentHandler(),
	new RateLimitHandler(),
	]);

The Kiota default handlers are created every time, so they get a new instance per client. But these 3 static handlers are re-used for every client, which results in the _operationStarted = true being set on the handler the first time any client has issued a request.

When ChainHandlersCollectionAndGetFirstLink is called, it attempts to set the InnerHandler on each handler in the chain:

This results in an exception, when trying to set the InnerHandler:

The exception is:

      System.InvalidOperationException: This instance has already started one or more requests. Properties can only be modified before sending the first request.
         at System.Net.Http.DelegatingHandler.CheckDisposedOrStarted()
         at System.Net.Http.DelegatingHandler.set_InnerHandler(HttpMessageHandler value)
         at GitHub.Octokit.Client.ClientFactory.ChainHandlersCollectionAndGetFirstLink(HttpMessageHandler finalHandler, DelegatingHandler[] handlers)
         at GitHub.Octokit.Client.ClientFactory.Build()