### 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)

if (p_property.name == "current_animation") {
		List<String> names;
		for (const KeyValue<StringName, AnimationData> &E : animation_set) {
			names.push_back(E.key);
		}
		names.sort();
		names.push_front("[stop]");
		String hint;
		for (List<String>::Element *E = names.front(); E; E = E->next()) {
			if (E != names.front()) {
				hint += ",";
			}
			hint += E->get();
		}
		p_property.hint_string = hint;
	}
}
void AnimationPlayer::_get_property_list(List<PropertyInfo> *p_list) const {