build: [Many APIs] add scripts to publish to Bazel Central Registry (BCR)#14161

ohmayr merged 4 commits intomaingoogleapis/google-cloud-python:mainfrom

owl-bot-copy-b9a11c037b823edbf442googleapis/google-cloud-python:owl-bot-copy-b9a11c037b823edbf442Copy head branch name to clipboard