Trying to use `caller()` after an unrelated call fails.

**Describe the bug**
Inserting the `caller()` block in a macro after making a call says that `caller` hasn't been defined.

**To Reproduce**
```jinja
{% macro button() %}
    {% call svg::render() %}{% endcall %}
    {{ caller() }}
{% endmacro %}
```
**Askama version**
Latest github commit

**Rust version**
1.87.0