tuples as chunk only available since pgsql 17

Author: devnexen

ext/pgsql/pgsql.stub.php

@@ -245,11 +245,13 @@
      * @cvalue PGRES_TUPLES_OK
      */
     const PGSQL_TUPLES_OK = UNKNOWN;
+#ifdef HAVE_PG_SET_CHUNKED_ROWS_MODE
     /**
      * @var int
      * @cvalue PGRES_TUPLES_CHUNK
      */
     const PGSQL_TUPLES_CHUNK = UNKNOWN;
+#endif
     /**
      * @var int
      * @cvalue PGRES_COPY_OUT