LONDON (Reuters) – British Airways staff at London’s Heathrow voted on Thursday in favour of a strike for better pay, threatening disruption at Britain’s busiest airport during an already chaotic summer for air travellers. The GMB union said 95% of those British Airways (BA) staff at Heathrow airport who voted chose to carry out a strike after BA failed to meet their demands for a 10% pay cut imposed during the pandemic to be rolled back. Around 700 workers had been balloted, of which 80% voted. Dates for the strike are likely to be during the peak summer holiday period, GMB said. Workers must…