chore(python): rename default branch to main#935

parthea merged 4 commits intomaingoogleapis/python-bigquery:mainfrom

owl-bot-update-lock-0ffe3bdd6c7159692df5f7744da74e5ef19966288a6bf76023e8e04e0c424d7dgoogleapis/python-bigquery:owl-bot-update-lock-0ffe3bdd6c7159692df5f7744da74e5ef19966288a6bf76023e8e04e0c424d7dCopy head branch name to clipboard