Remove support of returning for SQLite

Backed out changeset 989eeee984e4

The SQLite implementation of returning is partial so we can not yet use it as
long as the limitations are not solved:
https://www.sqlite.org/lang_returning.html#limitations_and_caveats

Closes #12288

trytond/trytond/backend/sqlite/database.py

@@ -455,9 +455,6 @@ class Database(DatabaseInterface):
     def put_connection(self, connection=None, close=False):
         pass
 
-    def has_returning(self):
-        return sqlite.sqlite_version_info >= (3, 35, 0)
-
     def close(self):
         if self.name == ':memory:':
             return