### 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)

}
					if (aa->audio_stream_playback.is_null()) {
						aa->audio_stream_playback = aa->object->call(SNAME("get_stream_playback"));
					}
					TrackNodeCache::PlayingAudioStreamInfo pasi;
					pasi.index = aa->audio_stream_playback->play_stream(stream, start_ofs);
					pasi.start = p_time;
					if (len && end_ofs > 0) { 
						pasi.len = len - start_ofs - end_ofs;
					} else {
						pasi.len = 0;
					}
					map[idx] = pasi;
				}
			} break;
			case Animation::TYPE_ANIMATION: {
				if (is_stopping) {
					continue;
				}
				AnimationPlayer *player = Object::cast_to<AnimationPlayer>(nc->node);
				if (!player) {
					continue;
				}
				if (p_seeked) {
					
					int idx = a->track_find_key(i, p_time);
					if (idx < 0) {
						continue;
					}
					double pos = a->track_get_key_time(i, idx);