migrations: don't check existing type before jsonb migration (#43131)

passerelle/utils/db.py

@@ -35,16 +35,9 @@ class EnsureJsonbType(Operation):
         _, column_name = field.get_attname_column()
         with schema_editor.connection.cursor() as cursor:
             cursor.execute(
-                'SELECT data_type FROM information_schema.columns WHERE table_name = %s AND '
-                'column_name = %s;', (table_name, column_name)
+                'ALTER TABLE {table} ALTER COLUMN {col} TYPE jsonb USING {col}::jsonb;'
+                .format(table=table_name, col=column_name)
             )
-            current_type = cursor.fetchone()[0].lower()
-            if current_type != 'jsonb':
-                assert current_type in ('json', 'text')
-                cursor.execute(
-                    'ALTER TABLE {table} ALTER COLUMN {col} TYPE jsonb USING {col}::jsonb;'
-                    .format(table=table_name, col=column_name)
-                )
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         pass