chore: update python post processor base image#2089

feywind merged 5 commits intomaingoogleapis/nodejs-pubsub:mainfrom

owl-bot-update-lock-84adf917cad8f48c61227febebae7af619882d7c8863d6ab6290a77d45a372cfgoogleapis/nodejs-pubsub:owl-bot-update-lock-84adf917cad8f48c61227febebae7af619882d7c8863d6ab6290a77d45a372cfCopy head branch name to clipboard