report cancelled pull after another one failed

[ndeloof]

What I did

As a pull error occurs, concurrent pull get ctx cancelled, but http/transport returns the context.Cause (https://github.com/golang/go/blob/master/src/net/http/transport.go#L669) and we don't get a "context cancelled" error but the original error to cancel the errgroup.

As a workaround, detect context is cancelled and report pull has been interrupted

Related issue
fixes #12767

(not mandatory) A picture of a cute animal, if possible in relation to what you did

$ cat compose.yaml 
services:
  test:
    image: alpine
  fail:
    image: none

$ docker compose  pull
[+] Pulling 2/2
 ✘ fail Error   pull access denied for none, repository does not exist or may require 'docker login'                                                                   0.8s 
 ! test Warning Interrupted                                                                                                                                            0.8s 
Error response from daemon: pull access denied for none, repository does not exist or may require 'docker login'