fix iceberg detection

dlt/destinations/athena/athena.py

@@ -308,10 +308,10 @@ def _get_column_def_sql(self, c: TColumnSchema) -> str:
 
     def _get_table_update_sql(self, table_name: str, new_columns: Sequence[TColumnSchema], generate_alter: bool) -> List[str]:
 
-        create_only_iceberg_tables = self.config.iceberg_bucket_url is not None and not self.in_staging_mode
+        iceberg_only_mode = self.config.iceberg_bucket_url and not self.in_staging_mode
 
         bucket = self.config.staging_config.bucket_url
-        if create_only_iceberg_tables:
+        if iceberg_only_mode:
             bucket = self.config.iceberg_bucket_url
 
         # TODO: we need to strip the staging layout from the table name, find a better way!
@@ -320,7 +320,7 @@ def _get_table_update_sql(self, table_name: str, new_columns: Sequence[TColumnSc
 
         # for the system tables we need to create empty iceberg tables to be able to run, DELETE and UPDATE queries
         # or if we are in iceberg mode, we create iceberg tables for all tables
-        is_iceberg = (self.schema.tables[table_name].get("write_disposition", None) == "skip") or create_only_iceberg_tables
+        is_iceberg = (self.schema.tables[table_name].get("write_disposition", None) == "skip") or iceberg_only_mode
         columns = ", ".join([self._get_column_def_sql(c) for c in new_columns])
 
         # this will fail if the table prefix is not properly defined