PHILADELPHIA — Republican Senate candidate Mehmet Oz has derided big technology companies as a “cartel” and boasted about taking on the Silicon Valley giants as he campaigns in Pennsylvania. But he’s also deeply invested in them. Oz’s personal financial disclosure report, filed Wednesday night, shows millions of dollars in Amazon, Apple, Google and Microsoft stock. Those are just part of a massive array of assets, from equities to real estate, that come from both his own career as a surgeon and TV star, and his wife’s significant family fortune. The candidate and his wife have assets worth bet…