test: refactor test-esm-namespace.mjs

Remove unused `name` argument that is different from a subsequent `name`
argument in a different but nearby function. This was mildly confusing
to me at first, so hopefully this change clarifies things for others
reading the test.

PR-URL: #25117
Reviewed-By: James M Snell <jasnell@gmail.com>

test/es-module/test-esm-namespace.mjs

@@ -6,7 +6,7 @@ import Module from 'module';
 
 const keys = Object.entries(
   Object.getOwnPropertyDescriptors(new Module().require('fs')))
-  .filter(([name, d]) => d.enumerable)
+  .filter(([ , d]) => d.enumerable)
   .map(([name]) => name)
   .concat('default')
   .sort();