refactor: remove setTimestamp() because it only returns parent method

Author: kenjis

system/I18n/TimeTrait.php

@@ -685,21 +685,6 @@ public function setTimezone($timezone)
         return static::createFromInstance($this->toDateTime()->setTimezone($timezone), $this->locale);
     }
 
-    /**
-     * Returns a new instance with the date set to the new timestamp.
-     *
-     * @param int $timestamp
-     *
-     * @return static
-     *
-     * @throws Exception
-     */
-    #[ReturnTypeWillChange]
-    public function setTimestamp($timestamp)
-    {
-        return parent::setTimestamp($timestamp);
-    }
-
     // --------------------------------------------------------------------
     // Add/Subtract
     // --------------------------------------------------------------------