By Ayeesha Walsh Britney Spears has showcased her toned physique while posing in a vibrant pink bikini. The chart-topping star was seen relaxing by the pool in her latest Instagram upload as she lay on a lounger topping up her tan. She wore her long blonde hair loose and in her trademark crimped waves as she posed for her fans. Britney, 42, drew comparisons between herself and Hollywood star Katie Holmes as she captioned the post. She wrote: “My first high waisted bathing suit… Feeling very Katie Holmes today!!! Ps sun’s out buns out !!!” Britney used the soundtrack of Beyonce’s new country tr…