Zendaya may not be ready to become Mrs. Tom Holland just yet! According to an insider close to the Challengers actress, 27, her longtime love, also 27, reportedly wants to take their relationship to the next level. However, the A-lister isn’t OK with slowing down her booming career to become a wife. “They’ve been dating for a long time, years in fact, and moved in together not too long ago,” the source claimed of the Hollywood power couple. “They have a solid relationship, and Tom would like to make things official.” Despite the British star’s wishes, Zendaya has been laser-focused on her illu…