### 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)

Node *child = parent->get_node_and_resource(a->track_get_path(i), resource, leftover_path);
		ERR_CONTINUE_MSG(!child, "On Animation: '" + p_anim->name + "', couldn't resolve track:  '" + String(a->track_get_path(i)) + "'."); 
		ObjectID id = resource.is_valid() ? resource->get_instance_id() : child->get_instance_id();
		int bone_idx = -1;
		int blend_shape_idx = -1;
#ifndef _3D_DISABLED
		if (a->track_get_path(i).get_subname_count() == 1 && Object::cast_to<Skeleton3D>(child)) {
			Skeleton3D *sk = Object::cast_to<Skeleton3D>(child);
			bone_idx = sk->find_bone(a->track_get_path(i).get_subname(0));
			if (bone_idx == -1) {
				continue;
			}
		}
		if (a->track_get_type(i) == Animation::TYPE_BLEND_SHAPE) {
			MeshInstance3D *mi_3d = Object::cast_to<MeshInstance3D>(child);
			if (!mi_3d) {
				continue;
			}
			if (a->track_get_path(i).get_subname_count() != 1) {
				continue;
			}
			blend_shape_idx = mi_3d->find_blend_shape_by_name(a->track_get_path(i).get_subname(0));
			if (blend_shape_idx == -1) {
				continue;
			}
		}
#endif 
		if (!child->is_connected("tree_exiting", callable_mp(this, &AnimationPlayer::_node_removed))) {
			child->connect("tree_exiting", callable_mp(this, &AnimationPlayer::_node_removed).bind(child), CONNECT_ONE_SHOT);
		}