### 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 (p_time < first_key_time) {
						double c = Math::ease(p_time / first_key_time, transition);
						Variant first_value = a->track_get_key_value(i, first_key);
						first_value = post_process_key_value(a, i, first_value, nc->node);
						Variant interp_value = Animation::interpolate_variant(pa->capture, first_value, c);
						if (pa->accum_pass != accum_pass) {
							ERR_CONTINUE(cache_update_prop_size >= NODE_CACHE_UPDATE_MAX);
							cache_update_prop[cache_update_prop_size++] = pa;
							pa->value_accum = interp_value;
							pa->accum_pass = accum_pass;
						} else {
							pa->value_accum = Animation::interpolate_variant(pa->value_accum, interp_value, p_interp);
						}
						continue; 
					}
				}
				if (update_mode == Animation::UPDATE_CONTINUOUS || update_mode == Animation::UPDATE_CAPTURE) {
					Variant value = a->value_track_interpolate(i, p_time);
					if (value == Variant()) {
						continue;
					}
					value = post_process_key_value(a, i, value, nc->node);
					if (pa->accum_pass != accum_pass) {
						ERR_CONTINUE(cache_update_prop_size >= NODE_CACHE_UPDATE_MAX);
						cache_update_prop[cache_update_prop_size++] = pa;
						pa->value_accum = value;
						pa->accum_pass = accum_pass;
					} else {
						pa->value_accum = Animation::interpolate_variant(pa->value_accum, value, p_interp);
					}