What can I do when this 'Required software update' errors-out with the message 'Installation Failed'?

What can I do when this 'Required software update' installation errors-out with the message 'Installation Failed'?

This same issue keeps occurring repeatedly on two of my Macs, both running macOS Catalina 10.15.7, a 2012 Mac mini, and a 2015 MacBook Air when I try to connect a 2020 iPhone SE to either system. Both computers seem to actually connect to the phone with a genuine Apple USB-A to Lightning cable (the one originally supplied with the phone.) I'm able to transfer photos from phone to each Mac, and to back up phone contents to each Mac using Finder.