fix: remove unused undefined param $raw

It is not defined in the interface and other classes, and not used at all.

system/Test/Mock/MockCache.php

@@ -92,11 +92,10 @@ public function remember(string $key, int $ttl, Closure $callback)
  * @param string $key Cache item name
  * @param mixed $value the data to save
  * @param int $ttl Time To Live, in seconds (default 60)
- * @param bool $raw Whether to store the raw value.
  *
  * @return bool
  */
- public function save(string $key, $value, int $ttl = 60, bool $raw = false)
+ public function save(string $key, $value, int $ttl = 60)
  {
  if ($this->bypass) {
  return false;