WASHINGTON—The number of Americans collecting unemployment benefits slid last week, another sign that the job market continues to recover rapidly from the coronavirus recession. Jobless claims dropped by 24,000 to 400,000 last week, the Labor Department reported Thursday. The weekly applications have fallen more or less steadily this year—from a peak of 904,000 in early January. But they remain high by historic standards: Before COVID-19 struck the United States in March 2020, claims were coming in at about 220,000 a week. The job market and overall economy have been recovering from the collapse of the spring of 2020. The rollout of vaccines this year has encouraged businesses to reopen or expand their hours and sent cooped-up consumers back out to visit restaurants, bars, and shops. Still, the health crisis isn’t over. COVID-19 cases are ticking up as the highly contagious delta variant spreads. The United States is reporting an average …