test: remove error message checking in test-worker-init-failure

Let the check for the error code suffice and don't check for a
particular string in the message.

Fixes: nodejs#33759

test/parallel/test-worker-init-failure.js

@@ -35,7 +35,6 @@ if (process.argv[2] === 'child') {
     // (i.e. single cpu) `ulimit` may not lead to such an error.
 
     worker.on('error', (e) => {
-      assert.match(e.message, /EMFILE/);
       assert.ok(e.code === 'ERR_WORKER_INIT_FAILED' || e.code === 'EMFILE');
     });
   }