fix template invalidation when migrating to 5.0

TODO.txt

@@ -1,8 +1,5 @@
 # @TODO
 
-## 5.0
-- fix template invalidation when migrating to 5.0. https://github.com/smarty-php/smarty/pull/852#issuecomment-1412728329
-
 ## CI-building optimization
 - compiled & cached templates should not contain references to local filesystem paths. Add an optional rootpath param
   to `(add|set)TemplateDir` or as a separate method. Make it default to `getcwd()`. If a relative path is passed to

src/Template/Compiled.php

@@ -294,4 +294,9 @@ class Compiled extends GeneratedPhpFile {
 		return $is_valid && !function_exists($properties['unifunc']);
 	}
 
+	/**
+	 * This method is here only to fix an issue when upgrading from Smarty v4 to v5.
+	 */
+	public function _decodeProperties($a, $b, $c = false): bool { return false; }
+
 }