Skip fpm bug #74083 test on Windows

Have not expected side effects of `include`.

Author: plmnikulin

sapi/fpm/tests/bug74083-concurrent-reload.phpt

@@ -2,6 +2,7 @@
 Concurrent reload signals should not kill PHP-FPM master process. (Bug: #74083)
 --SKIPIF--
 <?php
+include "skipif.inc";
 if (getenv("SKIP_SLOW_TESTS")) die("skip slow test");
 ?>
 --FILE--