fix: propagate context deadline exceeded error properly

When a shim becomes unresponsive (e.g., stopped via SIGSTOP), ttrpc
communication times out with `context deadline exceeded`.

Currently, this error is not properly propagated, causing redundant API
calls and slow container listing by client sides.

Specifically, when executing the API to check the task state, it appears
that the `context deadline exceeded` error via ttrpc is not being handled
within `shimTask.State()` and `getProcessState()`.

As a result, when this error occurs, clients such as nerdctl cannot
recognize this error, and it is thought that the issue described below is
occurring:

- https://github.com/containerd/nerdctl/issues/4720

Therefore, this commit adds error handling to ensure timeouts are properly
handled by client sides.

Signed-off-by: Hayato Kiwata <dev@haytok.jp>

core/runtime/v2/shim.go

@@ -835,6 +835,9 @@ func (s *shimTask) State(ctx context.Context) (runtime.State, error) {
 		ID: s.ID(),
 	})
 	if err != nil {
+		if errdefs.IsDeadlineExceeded(err) {
+			return runtime.State{}, err
+		}
 		if !errors.Is(err, ttrpc.ErrClosed) {
 			return runtime.State{}, errgrpc.ToNative(err)
 		}

plugins/services/tasks/local.go

@@ -349,7 +349,7 @@ func getProcessState(ctx context.Context, p runtime.Process) (*task.Process, err
 
 	state, err := p.State(ctx)
 	if err != nil {
-		if errdefs.IsNotFound(err) || errdefs.IsUnavailable(err) {
+		if errdefs.IsNotFound(err) || errdefs.IsUnavailable(err) || errdefs.IsDeadlineExceeded(err) {
 			return nil, err
 		}
 		log.G(ctx).WithError(err).Errorf("get state for %s", p.ID())