A lot of terran animals are intelligent. And many of those are sentient. Think elephants, dolphins, nonhuman apes, dogs. We do not know if and how many of the dinos were sentient, but I would not be surprised if many of them were. So extraterrestrial intelligent and sentient life? Quite likely and I would say, inevitable. What you mean though is technologically minded life forms. For that, you have to realise that there have been several different species of humans besides homo sapiens sapiens in the past. Again, we do not know if any of the dinosaurs were technologically capable, but time has a way to wipe away traces, so we will never know, but based on what we do know is that techno species will only arise if the evolutionary pressure pushes them in that direction, which is almost never the case.