feat(postgres): backport stream dialectOption to v6 (#16868)

src/dialects/postgres/connection-manager.js

@@ -123,7 +123,10 @@ class ConnectionManager extends AbstractConnectionManager {
           'lock_timeout',
           // Postgres allows additional session variables to be configured in the connection string in the `options` param.
           // see [https://www.postgresql.org/docs/14/libpq-connect.html#LIBPQ-CONNECT-OPTIONS]
-          'options'
+          'options',
+          // The stream acts as a user-defined socket factory for postgres. In particular, it enables IAM autentication
+          // with Google Cloud SQL. see: https://github.com/sequelize/sequelize/issues/16001#issuecomment-1561136388
+          'stream',
         ]));
     }