child_process: remove unused argument

The internal validateTimeout() takes a single parameter, so do not pass
a second value.

lib/child_process.js

@@ -600,7 +600,7 @@ function abortChildProcess(child, killSignal) {
 
 function spawn(file, args, options) {
   options = normalizeSpawnArguments(file, args, options);
-  validateTimeout(options.timeout, 'options.timeout');
+  validateTimeout(options.timeout);
   validateAbortSignal(options.signal, 'options.signal');
   const killSignal = sanitizeKillSignal(options.killSignal);
   const child = new ChildProcess();