This past weekend, Boston Calling made its very long-awaited return to Harvard University Athletics Intricate soon after two many years of cancellations, and for a second — as Friday’s overcast skies gave way to a sunny afternoon just as the main gates opened — it appeared that the festival’s luck might be shifting for the much better. It had been a tough 3 many years: contacting off the fest in 2020 and 2021, acquiring 3 alternative headliners for 2022, setting up a key function amid swelling COVID variants. But as Paris Jackson and Pom Pom Squad warmed up Friday’s early crowds, the temper was optimistic. By the time British glam-rock…