Mariah Carey has carried on her new year tradition of jumping into a jacuzzi in a posh frock. The ‘All I Want for Christmas is You’ singer, 54, has spent years treating her fans to online updates showing her taking a dip in hot tubs in Louis Vuitton or Tom Ford gowns in spots from the Dominican Republic to Aspen. Her latest video showing her carrying on the tradition showed her wearing a full-length red sparkling dress as she lowered herself into a steaming hot tub. She captioned the clip: “Wishing us all a healthy, peaceful and a happy new year! (red heart emoji.) Newly-single Mariah also kep…