LONDON, Dec 11 (Reuters) - Britain reported 54,073 new COVID-19 cases on Saturday and 132 more deaths within 28 days of a positive test, official data showed. The figures compared to 58,194 cases and 120 deaths reported on Friday. Earlier, the UK Health Security Agency said 633 additional cases of the Omicron variant had been reported across the United Kingdom, taking the total to 1,898. Reporting by Michael Holden, Editing by William Maclean