LOS ANGELES—Mayor Eric Garcetti, who had been isolating in Glasgow, Scotland, after testing positive for COVID-19, is traveling to Washington today before returning to Los Angeles Tuesday. No reason was given for Garcetti’s D.C. trip after he previously announced plans to return to Los Angeles Sunday. But on Monday, President Joe Biden is scheduled to sign the $1 trillion infrastructure bill approved by Congress this month and is expected to be joined by several governors, mayors, and labor and business leaders. Following the bill’s approval, Garcetti hailed it as providing a golden opportunity for major improvements in Los Angeles. “Investments in public transportation, bridges, clean energy and water systems, and broadband are the building blocks of a prosperous future for Los Angeles,” he said. “We’re already investing billions of dollars in infrastructure locally, and these funds are a chance to double down on that work to protect public health, fortify …