fix: dont error when field has no metadata. (#221)

Author: marianogappa

cloudquery/sdk/schema/column.py

@@ -59,7 +59,7 @@ def to_arrow_field(self):
 
     @staticmethod
     def from_arrow_field(field: pa.Field) -> Column:
-        metadata = field.metadata
+        metadata = field.metadata or {}
         primary_key = metadata.get(arrow.METADATA_PRIMARY_KEY) == arrow.METADATA_TRUE
         unique = metadata.get(arrow.METADATA_UNIQUE) == arrow.METADATA_TRUE
         incremental_key = (