LONDON — Voting for members of local councils usually involves debates about filling potholes and regularizing bin collections. This year, however, geopolitics thousands of miles away will shape how Brits cast their ballots. The incumbent, unpopular center-left Labour government faces a challenge from the left in Thursday’s local elections in numerous urban centers, including many of London’s 32 boroughs, by the newly energized Greens. Reform is targeting the Tories in outer London. Led by self-