fix: Handle complex Spark data types in SparkSource (#3154)

* Make sure data types are strings

Signed-off-by: Petra Rebernjak <petra@noom.com>

* Lint

Signed-off-by: Petra Rebernjak <petra@noom.com>

Signed-off-by: Petra Rebernjak <petra@noom.com>

sdk/python/feast/infra/offline_stores/contrib/spark_offline_store/spark_source.py

@@ -159,10 +159,7 @@ def get_table_column_names_and_types(
             store_config=config.offline_store
         )
         df = spark_session.sql(f"SELECT * FROM {self.get_table_query_string()}")
-        return (
-            (fields["name"], fields["type"])
-            for fields in df.schema.jsonValue()["fields"]
-        )
+        return ((field.name, field.dataType.simpleString()) for field in df.schema)
 
     def get_table_query_string(self) -> str:
         """Returns a string that can directly be used to reference this table in SQL"""