`angle` argument to `element_text()` does not work for `label_text`

Example:

```python
ggplot() + \
geom_crossbar(ymin=-1, ymax=1, labels=layer_labels().line("Text")) + \
theme(label_text=element_text(size=30, angle=45))
```

Output:

Expected:

No source file or test is named. Start by running the provided Python plotting example and compare the rendered label with the expected image; then trace the label_text rendering path. Done means element_text(angle=45) visibly rotates the label as shown in the expected output.

Written by the indexing model from the issue text.