Client closing the socket does not cause a CancellationError on the server

We have found that a server that is async-waiting after receiving a HTTP request does not see a CancellationError if the client were to close the connection.

This is trivially reproducible.

Server code:

let logger = Logger(label: "TestHTTPServer")
let server = NIOHTTPServer(logger: logger, configuration: .init(bindTarget: .hostAndPort(host: "127.0.0.1", port: 12345)))
try await server.serve { request, requestContext, requestBodyAndTrailers, responseSender in
    print("STALLING...")
    try await Task.sleep(for: .seconds(60 * 60))
}

Client terminal:

$ curl -v http://localhost:12345/stall
* Host localhost:12345 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
*   Trying [::1]:12345...
* connect to ::1 port 12345 from ::1 port 57145 failed: Connection refused
*   Trying 127.0.0.1:12345...
* Connected to localhost (127.0.0.1) port 12345
> GET /stall HTTP/1.1
> Host: localhost:12345
> User-Agent: curl/8.7.1
> Accept: */*
> 
* Request completely sent off
^C

Server output:

STALLING...

The server hangs even though the client has closed the socket. Note how there is no exception or additional printing in the server output.

Start with the NIOHTTPServer serve closure shown in the issue and reproduce the stalled request with the provided server and curl commands. Trace how client socket closure reaches the async request handler, then verify that closing the client causes the server-side wait to receive a CancellationError rather than continuing to hang.