Add missing isolation test for test_decoding in meson build

Oversight in 7f13ac8, where catalog_change_snapshot was missing from the
list in meson.build.

Author: Hayato Kuroda
Discussion: https://postgr.es/m/TYAPR01MB58662C932F45A13C6F9BE352F5259@TYAPR01MB5866.jpnprd01.prod.outlook.com

Author: michaelpq

contrib/test_decoding/meson.build

@@ -49,6 +49,7 @@ tests += {
       'mxact',
       'delayed_startup',
       'ondisk_startup',
+      'catalog_change_snapshot',
       'concurrent_ddl_dml',
       'oldest_xmin',
       'snapshot_transfer',