Increase PHPStan rule level to 10

phpstan.neon

@@ -1,4 +1,4 @@
 parameters:
-    level: 9
+    level: 10
     paths:
         - src

src/Version.php

@@ -10,9 +10,11 @@
 namespace SebastianBergmann;
 
 use const DIRECTORY_SEPARATOR;
+use function assert;
 use function end;
 use function explode;
 use function fclose;
+use function is_array;
 use function is_dir;
 use function is_resource;
 use function proc_close;
@@ -97,6 +99,10 @@ private function getGitInformation(string $path): false|string
             return false;
         }
 
+        assert(is_array($pipes));
+        assert(isset($pipes[1]) && is_resource($pipes[1]));
+        assert(isset($pipes[2]) && is_resource($pipes[2]));
+
         $result = trim((string) stream_get_contents($pipes[1]));
 
         fclose($pipes[1]);