Apply tidy to SKIPIF and CLEAN section as well

scripts/dev/tidy.php

@@ -117,7 +117,7 @@ function transformTestCode(string $code, callable $transformer): string {
     }
 
     return preg_replace_callback(
-        '/(--FILE--)(.+?)(--[A-Z_]+--)/s',
+        '/(--(?:FILE|SKIPIF|CLEAN)--)(.+?)(--[A-Z_]+--)/s',
         function(array $matches) use($transformer) {
             return $matches[1] . $transformer($matches[2]) . $matches[3];
         },