Fix spark list relation without caching

docs/source/_static/dbt_project/macros/spark_adapter.sql

@@ -0,0 +1,7 @@
+{% macro spark__list_relations_without_caching(relation) %}
+  {% call statement('list_relations_without_caching', fetch_result=True) -%}
+    show table extended in {{ relation }} like '*'
+  {% endcall %}
+
+  {% do return(load_result('list_relations_without_caching').table) %}
+{% endmacro %}