test: skip fs.watch() test on IBMi

We've added pummel tests to CI, so we need to add a skip for IBMi for
the fs.watch() test there as we have for all the fs.watch() tests
elsewhere.

PR-URL: https://github.com/nodejs/node/pull/38192
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

test/pummel/test-fs-watch-non-recursive.js

@@ -21,6 +21,11 @@
 
 'use strict';
 const common = require('../common');
+
+if (common.isIBMi) {
+  common.skip('IBMi does not support fs.watch()');
+}
+
 const path = require('path');
 const fs = require('fs');