By Daniel Moxon Oscar Piastri has vowed to continue racing hard after proving to Formula 1 rivals he is no pushover. The Aussie came into the sport last year with a huge reputation having dominated throughout his progression up the single-seater ladder. And the pressure mounted further after his public and ugly switch from Alpine to join rivals McLaren for his debut season. But he thrived under the scrutiny and produced one of the best rookie campaigns since Lewis Hamilton first burst onto the scene in 2007. And Piastri thinks he did a good job of proving to his fellow F1 stars that he is not …