### 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_cache->skeleton = nullptr;
						node_cache->node_3d = nullptr;
						ERR_CONTINUE(node_cache->bone_idx < 0);
					}
					Transform3D rest = node_cache->skeleton->get_bone_rest(bone_idx);
					node_cache->init_loc = rest.origin;
					node_cache->init_rot = rest.basis.get_rotation_quaternion();
					node_cache->init_scale = rest.basis.get_scale();
				} else {
					
					node_cache->skeleton = nullptr;
				}
			}
			switch (a->track_get_type(i)) {
				case Animation::TYPE_POSITION_3D: {
					node_cache->loc_used = true;
				} break;
				case Animation::TYPE_ROTATION_3D: {
					node_cache->rot_used = true;
				} break;
				case Animation::TYPE_SCALE_3D: {
					node_cache->scale_used = true;
				} break;
				default: {
				}
			}
		}
		if (a->track_get_type(i) == Animation::TYPE_BLEND_SHAPE) {