Boris Johnson was warned by Dominic Cummings that he could "kill the Queen" by infecting her with coronavirus, it has been claimed.The alleged incident occurred in March 2020, the month in which then-Prime Minister Johnson imposed a nationwide lockdown amid the Covid-19 pandemic.Prime ministers usually hold a weekly audience with the monarch, which tends to occur on a Wednesday.At the time, Mr Johnson had been attempting to organise his weekly a…