By Andrew Chung WASHINGTON (Reuters) -The U.S. Supreme Court sided with President Joe Biden on Thursday as he seeks to end a hardline immigration policy begun under his predecessor Donald Trump that forced tens of thousands of migrants to stay in Mexico to await U.S. hearings on their asylum claims. The justices, in a 5-4 ruling authored by Chief Justice John Roberts, overturned a federal appeals court decision requiring Biden to restart Trump’s “remain in Mexico” policy after the Republican-led states of Texas and Missouri sued to maintain the program. The ruling is a victory for Biden, who a…