Merge pull request containerd#10524 from k8s-infra-cherrypick-robot/cherry-pick-10442-to-release/1.6

[release/1.6] client: fix tasks with PID 0 cannot be forced to delete

Author: estesp

task_opts.go

@@ -158,6 +158,12 @@ type ProcessDeleteOpts func(context.Context, Process) error
 
 // WithProcessKill will forcefully kill and delete a process
 func WithProcessKill(ctx context.Context, p Process) error {
+	// Skip killing tasks with PID 0
+	// https://github.com/containerd/containerd/issues/10441
+	if p.Pid() == 0 {
+		return nil
+	}
+
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	// ignore errors to wait and kill as we are forcefully killing