SAN FRANCISCO — For years, Latinos represented the biggest share of new HIV cases in this city, but testing data suggests the tide may be turning. The number of Latinos newly testing positive for HIV dropped 46% from 2022 to 2023, according to a preliminary report released in July by the San Francisco Department of Public Health. The decrease could mark the first time in five years that Latinos haven’t accounted for the largest number of new cases, leading to cautious optimism that the millions of dollars the city has spent to remedy the troubling disparity is working. But outreach workers and…