An Interventional, Open-label, Randomized, Multicenter Phase 3 Study of PF-07220060 plus Letrozole Compared to CDK4/6 Inhibitor Plus Letrozole in Participants over 18 Years with Hormone Receptor (HR)-Positive, HER2-Negatrive Advanced/Metastatic Breast Cancer Who Have Not Received Any Prior Systemic Anti-Cancer Treatment for Advanced/Metastatic Disease