### 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("add_animation_library", "name", "library"), &AnimationPlayer::add_animation_library);
	ClassDB::bind_method(D_METHOD("remove_animation_library", "name"), &AnimationPlayer::remove_animation_library);
	ClassDB::bind_method(D_METHOD("rename_animation_library", "name", "newname"), &AnimationPlayer::rename_animation_library);
	ClassDB::bind_method(D_METHOD("has_animation_library", "name"), &AnimationPlayer::has_animation_library);
	ClassDB::bind_method(D_METHOD("get_animation_library", "name"), &AnimationPlayer::get_animation_library);
	ClassDB::bind_method(D_METHOD("get_animation_library_list"), &AnimationPlayer::_get_animation_library_list);
	ClassDB::bind_method(D_METHOD("has_animation", "name"), &AnimationPlayer::has_animation);
	ClassDB::bind_method(D_METHOD("get_animation", "name"), &AnimationPlayer::get_animation);
	ClassDB::bind_method(D_METHOD("get_animation_list"), &AnimationPlayer::_get_animation_list);
	ClassDB::bind_method(D_METHOD("animation_set_next", "anim_from", "anim_to"), &AnimationPlayer::animation_set_next);
	ClassDB::bind_method(D_METHOD("animation_get_next", "anim_from"), &AnimationPlayer::animation_get_next);
	ClassDB::bind_method(D_METHOD("set_blend_time", "anim_from", "anim_to", "sec"), &AnimationPlayer::set_blend_time);
	ClassDB::bind_method(D_METHOD("get_blend_time", "anim_from", "anim_to"), &AnimationPlayer::get_blend_time);
	ClassDB::bind_method(D_METHOD("set_default_blend_time", "sec"), &AnimationPlayer::set_default_blend_time);
	ClassDB::bind_method(D_METHOD("get_default_blend_time"), &AnimationPlayer::get_default_blend_time);
	ClassDB::bind_method(D_METHOD("play", "name", "custom_blend", "custom_speed", "from_end"), &AnimationPlayer::play, DEFVAL(""), DEFVAL(-1), DEFVAL(1.0), DEFVAL(false));
	ClassDB::bind_method(D_METHOD("play_backwards", "name", "custom_blend"), &AnimationPlayer::play_backwards, DEFVAL(""), DEFVAL(-1));
	ClassDB::bind_method(D_METHOD("pause"), &AnimationPlayer::pause);
	ClassDB::bind_method(D_METHOD("stop", "keep_state"), &AnimationPlayer::stop, DEFVAL(false));
	ClassDB::bind_method(D_METHOD("is_playing"), &AnimationPlayer::is_playing);
	ClassDB::bind_method(D_METHOD("set_current_animation", "anim"), &AnimationPlayer::set_current_animation);
	ClassDB::bind_method(D_METHOD("get_current_animation"), &AnimationPlayer::get_current_animation);
	ClassDB::bind_method(D_METHOD("set_assigned_animation", "anim"), &AnimationPlayer::set_assigned_animation);
	ClassDB::bind_method(D_METHOD("get_assigned_animation"), &AnimationPlayer::get_assigned_animation);
	ClassDB::bind_method(D_METHOD("queue", "name"), &AnimationPlayer::queue);
	ClassDB::bind_method(D_METHOD("get_queue"), &AnimationPlayer::get_queue);
	ClassDB::bind_method(D_METHOD("clear_queue"), &AnimationPlayer::clear_queue);