I don't think so but this has been requested a few times already. add one more button 'boot all AI'. would really help
But still one by one no? Then you might as well select their name in the window and use the boot button.
though this does appear to work, it has strange results. some AI are placed as spectators, some were completely removed from player list. as i was testing this command it some how removed my own ID from the players list even though i did not "callvote kick" myself, with my ID missing from the players list i was still on the server and able to enter the track. having to type the chat command and the AI name can be very cumbersome... example: /callvote kick Magnussen / O'Connell abbreviations do not work. it is much easier to just highlight the driver and vote/boot them.