By Elizabeth Piper, Kate Holton and Alistair Smout LONDON (Reuters) – British Prime Minister Liz Truss fired her finance minister Kwasi Kwarteng on Friday and scrapped parts of their economic package in a desperate bid to stay in power and survive the market and political turmoil gripping the country. The pound and British government bonds fell as a chastened Truss held an eight-minute news conference in Downing Street, with economists and investors saying her reversal of 20 billion pounds ($22 billion) of tax cuts was unlikely to calm febrile financial markets. Truss said she accepted she had…