By Pamela Barbaglia LONDON (Reuters) – Britain’s largest drugstore chain Boots has set a Feb. 24 deadline to receive indicative bids from a series of deep-pocketed investors that could value the 173-year-old firm at up to 8 billion pounds ($10.88 billion), two sources told Reuters. The sale will see U.S. drugstore giant Walgreens, which has backed Nottingham-based Boots since 2012, cashing out from one of Britain’s best-known retailers which operates more than 2,200 stores and employs about 51,000 people. It will also lead to the dismantling of the Walgreens Boots Alliance (WBA), which was set…