### Godot version

4.2 1ba920f

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

```GDScript
func _ready() -> void:
	$AnimationPlayer.play("new_animation")
	$AnimationPlayer.advance(0)
```
The animation has a single track with Update Mode set to discrete. It does not play, no matter the argument used.
Removing `advance()` will make it play.

Works correctly in rc1.

### Steps to reproduce

1. Run MRP on master
2. Run MRP in 4.2 rc1

### Minimal reproduction project

[brokedvance.zip](https://github.com/godotengine/godot/files/13460977/brokedvance.zip)

return speed_scale;
}
float AnimationPlayer::get_playing_speed() const {
	if (!playing) {
		return 0;
	}
	return speed_scale * playback.current.speed_scale;
}
void AnimationPlayer::seek(double p_time, bool p_update, bool p_update_only) {
	if (!active) {
		return;
	}
	playback.current.pos = p_time;
	if (!playback.current.from) {
		if (playback.assigned) {
			ERR_FAIL_COND_MSG(!animation_set.has(playback.assigned), vformat("Animation not found: %s.", playback.assigned));
			playback.current.from = &animation_set[playback.assigned];
		}
		if (!playback.current.from) {
			return; 
		}
	}
	playback.started = false; 
	playback.seeked = true;
	if (p_update) {
		_process_animation(0, p_update_only);
		playback.seeked = false; 
	}
}
void AnimationPlayer::advance(double p_time) {