Remove XFAIL for proc-idle-timeout.phpt

Author: bukka

sapi/fpm/tests/proc-idle-timeout.phpt

@@ -1,7 +1,5 @@
 --TEST--
 FPM: Process manager config pm.process_idle_timeout
---XFAIL--
-Frequently fails in CI
 --SKIPIF--
 <?php
 include "skipif.inc";