doc: remove duplicate options

PR-URL: nodejs/node#16339
Fixes: nodejs/node#16332
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>

doc/api/child_process.md

@@ -135,7 +135,6 @@ changes:
 
 * `command` {string} The command to run, with space-separated arguments.
 * `options` {Object}
-  * `timeout` {number} (Default: `0`)
   * `cwd` {string} Current working directory of the child process.
   * `env` {Object} Environment key-value pairs.
   * `encoding` {string} **Default:** `'utf8'`