Hours after Denver officials announced that more than 450 residents fatally overdosed here last year, Colorado lawmakers voted Wednesday to shelve a bill that would have allowed a safe-drug use site to open in the city. A bipartisan group of state senators on the Health and Human Services Committee voted to indefinitely postpone HB23-1202, six days after the bill’s sponsors scrambled to save it at an initial committee hearing that showed the measure didn’t have enough support to pass.