Skip bug70417.phpt if lsof output looks wrong

On alpine lsof accepts -p but it doesn't actually do anything.
Add a crude check for whether lsof looks like Linux lsof.

Author: nikic

ext/phar/tests/tar/bug70417.phpt

@@ -9,6 +9,9 @@ exec('lsof -p ' . getmypid(), $out, $status);
 if ($status !== 0) {
     die("skip lsof(8) not available");
 }
+if (!str_starts_with($out[0], 'COMMAND')) {
+    die("skip Might be a different lsof");
+}
 ?>
 --FILE--
 <?php