tty.getWindowSize is not a function inside a "worker_threads" worker (#3955)

Use "isTTY" instead of tty.isatty(fd)

Author: 1999

lib/reporters/base.js

@@ -25,7 +25,7 @@ exports = module.exports = Base;
  * Check if both stdio streams are associated with a tty.
  */
 
-var isatty = tty.isatty(1) && tty.isatty(2);
+var isatty = process.stdout.isTTY && process.stderr.isTTY;
 
 /**
  * Save log references to avoid tests interfering (see GH-3604).