Not long ago, big tech was splurging on flashy office space to woo talent. Money sloshed around and a hiring boom was under way. Even as the pandemic forced programmers and software engineers to work remotely, tech giants splashed out on lavish workplaces. Google has been beavering away on a sprawling complex in London with a 25-metre swimming pool and a rooftop running track, due to open in 2024, while shelling out $1bn on another building…