Migrate core code to using symfony/filesystem

webmozart/path-util is retained for plugin compatibility, but is dropped in 5.0

build/generate-known-translation-apis.php

@@ -25,7 +25,7 @@ namespace pocketmine\build\generate_known_translation_apis;
 
 use pocketmine\lang\Translatable;
 use pocketmine\utils\Utils;
-use Webmozart\PathUtil\Path;
+use Symfony\Component\Filesystem\Path;
 use function array_map;
 use function count;
 use function dirname;