Simone Biles Says She's Been Blocked On Social Media Amid Spat W/ MyKayla Skinner

11:07 AM PT -- Seems Simone Biles was, indeed, talking about MyKayla Skinner with her post on X ... Jordan Chiles just shared a snap of a phone that appeared to show Skinner has blocked the gymnastics superstar on Instagram. Simone Biles says she's…