bug: remove usage of deleted function is_version_below

Author: ZackeryRSmith

addons/mod_loader/internal/file.gd

@@ -195,10 +195,7 @@ static func file_exists_in_zip(zip_path: String, path: String) -> bool:
 	if not reader:
 		return false
 
-	if _ModLoaderGodot.is_version_below(_ModLoaderGodot.ENGINE_VERSION_HEX_4_2_0):
-		return reader.get_files().has(path.trim_prefix("res://"))
-	else:
-		return reader.file_exists(path.trim_prefix("res://"))
+	return reader.get_files().has(path.trim_prefix("res://"))
 
 
 static func get_mod_dir_name_in_zip(zip_path: String) -> String: