NSUrlSessionHandler.Dispose doesn't fully clean up

[dotMorten]

Apple platform

iOS

Framework version

net10.0-*

Affected platform version

.NET 8, 9 and 10

Description

When I try and create a background configuration for my NSUrlSessionHandler, I can't dispose that handler and create a new one later, since all requests will start timing out.

Steps to Reproduce

1. Run the following code more than once. After the first time, all requests will time out:

NSUrlSessionHandler handler = new NSUrlSessionHandler(NSUrlSessionConfiguration.CreateBackgroundSessionConfiguration("id"));
 var client = new HttpClient(handler);
 await client.GetByteArrayAsync("https://microsoft.com"); // Times out after the first run
 client.Dispose();
 handler.Dispose();

Did you find any workaround?

I can workaround it with reflection, which is too risky for deployment, but it does clearly indicate what the fix will be:

var field = typeof(NSUrlSessionHandler).GetField("session", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
NSUrlSession session = (NSUrlSession)field.GetValue(handler)!;
session.InvalidateAndCancel();

Judging from this, we just need to add that InvalidateAndCancel call to the Dispose method. There's also FinishTasksAndInvalidate which would fix the timeout, but when I call Dispose on SocketsHttpHandler, and pending requests are cancelled, so the InvalidateAndCancel seems most appropriate.

Relevant logs

No response