SAN FRANCISCO — Every year, thousands of bankers, venture capitalists, private equity investors, and other moneybags flock to San Francisco’s Union Square to pursue deals. Scores of security guards keep the homeless, the snoops, and the patent-stealers at bay, while the dealmakers pack into the cramped Westin St. Francis hotel and its surrounds to meet with cash-hungry executives from biotech and other health care companies. After a few years of pandemic slack, the 2024 J.P. Morgan Healthcare Conference regained its full vigor, drawing 8,304 attendees in early January to talk science, medicine…