Add newly created branch to Azure Pipelines

[hugovk]

To avoid needing manual PRs such as https://github.com/python/cpython/pull/109453, either PEP 101 or a script such as:

• Bump version numbers via the release script: $ .../release-tools/release.py --bump X.Y.ZaN

should be updated to add the new branch name to the triggers in https://github.com/python/cpython/blob/main/.azure-pipelines/ci.yml.