Lewis Hamilton has finally signed a new contract extension that will keep him at Mercedes alongside George Russell until the end of 2025. The seven-time world champion’s previous deal expired at the end of this season, meaning he had just four months remaining on it prior to the announcement on Thursday at the Italian Grand Prix. Hamilton has been with Mercedes since 2013, winning six of his seven championships with the team as well as 82 of his record 103 race victories. “We dream everyday of being the best and we have dedicated the past decade together to achieving that…