Suppress failure when reading $partitions system table in get_indexes

Not all connectors have a `$partitions` table. This caused `get_indexes`
to fail when called on a non-Hive (or non-partitioned Hive) table.

Since Trino engine doesn't have concept of partitions there's no single
way to fetch partition columns. One option is to parse the output of
`SHOW CREATE TABLE` to identify them but the logic would differ based on
what connector is being used. So we just opt to suppress the failure in
case of a non-Hive or non-partitioned Hive table instead.

trino/sqlalchemy/dialect.py

@@ -297,7 +297,12 @@ def get_indexes(self, connection: Connection, table_name: str, schema: str = Non
         if not self.has_table(connection, table_name, schema):
             raise exc.NoSuchTableError(f"schema={schema}, table={table_name}")
 
-        partitioned_columns = self._get_columns(connection, f"{table_name}$partitions", schema, **kw)
+        partitioned_columns = None
+        try:
+            partitioned_columns = self._get_columns(connection, f"{table_name}$partitions", schema, **kw)
+        except Exception as e:
+            # e.g. it's not a Hive table or an unpartitioned Hive table
+            logger.debug("Couldn't fetch partition columns. schema: %s, table: %s, error: %s", schema, table_name, e)
         if not partitioned_columns:
             return []
         partition_index = dict(