### Godot version

4.0.beta13

### System information

Windows 10

### Issue description

When you call the `seek()` function without a current animation it outputs `Condition "!playback.current.from" is true.` to the debugger.

I was getting the error above whenever I would call `stop()` on an AnimationPlayer when it didn't have a playing animation. I realized that `stop()` also calls the `seek()` function.

I would expect the `seek()` and `stop()` functions to just do nothing, instead of throwing errors, if there isn't a current animation, or at least show an error that says that there is no animation to seek/stop.

This is the same issue that was described here: [#6122](https://github.com/godotengine/godot/issues/6122)

### Steps to reproduce

- Create an AnimationPlayer node.
- Don't have it play any animations.
- Call the `seek()` function.

### Minimal reproduction project

[seek_issue.zip](https://github.com/godotengine/godot/files/10442071/seek_issue.zip)

clear_cache_needed = true;
						ad.animation = K.value;
						ad.animation_library = lib.name;
					}
					ad.last_update = animation_set_update_pass;
				}
			}
		}
	}
	
	List<StringName> to_erase;
	for (const KeyValue<StringName, AnimationData> &E : animation_set) {
		if (E.value.last_update != animation_set_update_pass) {
			
			to_erase.push_back(E.key);
			clear_cache_needed = true;
		}
	}
	while (to_erase.size()) {
		animation_set.erase(to_erase.front()->get());
		to_erase.pop_front();
	}
	if (clear_cache_needed) {
		
		clear_caches();
	}
	emit_signal(SNAME("animation_list_changed"));
}
void AnimationPlayer::_animation_added(const StringName &p_name, const StringName &p_library) {