### 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)

ClassDB::bind_method(D_METHOD("restore"), &AnimatedValuesBackup::restore);
}
#endif
bool AnimationPlayer::_set(const StringName &p_name, const Variant &p_value) {
	String name = p_name;
	if (name.begins_with("playback/play")) { 
		set_current_animation(p_value);
	} else if (name.begins_with("anims/")) {
		
		String which = name.get_slicec('/', 1);
		Ref<Animation> anim = p_value;
		Ref<AnimationLibrary> al;
		if (!has_animation_library(StringName())) {
			al.instantiate();
			add_animation_library(StringName(), al);
		} else {
			al = get_animation_library(StringName());
		}
		al->add_animation(which, anim);
	} else if (name.begins_with("libraries")) {
		Dictionary d = p_value;