chore(python): Use ubuntu 22.04 for Python 3.7 testing#537

gcf-owl-bot[bot] wants to merge 6 commits intomaingoogleapis/python-error-reporting:mainfrom

owl-bot-update-lock-68634701216dd3347e5a019ac43d42a9b9c45444ea5e2e7293d3f8ec32a5d74fgoogleapis/python-error-reporting:owl-bot-update-lock-68634701216dd3347e5a019ac43d42a9b9c45444ea5e2e7293d3f8ec32a5d74fCopy head branch name to clipboard