Cancel io if task is deleted without being started

This prevent a deadlock on Windows since no process is actually running
until `Start()` is called.

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

task.go

@@ -188,6 +188,7 @@ func (t *task) Wait(ctx context.Context) (uint32, error) {
 // during cleanup
 func (t *task) Delete(ctx context.Context) (uint32, error) {
 	if t.io != nil {
+		t.io.Cancel()
 		t.io.Wait()
 		t.io.Close()
 	}