Fix the schema-verifier in Cloud Build (#2812)

This is the same problem as the one that broke the Java test:

pg_dump upgrade to 17.6 added new meta command lines.

release/schema-verifier/allowed_diffs.txt

@@ -6,3 +6,5 @@ COMMENT ON EXTENSION pg_stat_statements IS 'track execution statistics of all SQ
 SET transaction_timeout = 0;
 SET default_table_access_method = heap;
 SET default_with_oids = false;
+^\\restrict
+^\\unrestrict