test: add test unknown credential error of process.setgroups

Added test to check ERR_UNKNOWN_CREDENTIAL of process.setgroups to
increase coverage.

PR-URL: nodejs#22368
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

test/parallel/test-process-setgroups.js

@@ -45,3 +45,10 @@ assert.throws(
     }
   );
 });
+
+assert.throws(() => {
+  process.setgroups([1, 'fhqwhgadshgnsdhjsdbkhsdabkfabkveyb']);
+}, {
+  code: 'ERR_UNKNOWN_CREDENTIAL',
+  message: 'Group identifier does not exist: fhqwhgadshgnsdhjsdbkhsdabkfabkveyb'
+});