### 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)

Variant res;
	if (GDVIRTUAL_CALL(_post_process_key_value, p_anim, p_track, p_value, const_cast<Object *>(p_object), p_object_idx, res)) {
		return res;
	}
	return _post_process_key_value(p_anim, p_track, p_value, p_object, p_object_idx);
}
Variant AnimationPlayer::_post_process_key_value(const Ref<Animation> &p_anim, int p_track, Variant p_value, const Object *p_object, int p_object_idx) {
	switch (p_anim->track_get_type(p_track)) {
#ifndef _3D_DISABLED
		case Animation::TYPE_POSITION_3D: {
			if (p_object_idx >= 0) {
				const Skeleton3D *skel = Object::cast_to<Skeleton3D>(p_object);
				return Vector3(p_value) * skel->get_motion_scale();
			}
			return p_value;
		} break;
#endif 
		default: {
		} break;
	}
	return p_value;
}
void AnimationPlayer::_animation_process_animation(AnimationData *p_anim, double p_prev_time, double p_time, double p_delta, float p_interp, bool p_is_current, bool p_seeked, bool p_started, Animation::LoopedFlag p_looped_flag) {