test: fix race condition in test-child-process-bad-stdio

test-child-process-bad-stdio.js contains a race condition between
a timeout in the test process and a timeout in the spawned child
process. This commit addresses the race condition by having the
child process wait indefinitely to be killed.

test/parallel/test-child-process-bad-stdio.js

@@ -3,7 +3,7 @@
 const common = require('../common');
 
 if (process.argv[2] === 'child') {
-  setTimeout(() => {}, common.platformTimeout(100));
+  setTimeout(() => {}, common.platformTimeout(1000));
   return;
 }