- Create a new branch based of master for major versions.
- Add a commit that pins dependencies like so: https://github.com/mitmproxy/docker-releases/commit/3d6a9989fde068ad0aea257823ac3d7986ff1613. The requirements can be obtained by creating a fresh venv, pip-installing the new wheel in there, and then running `pip freeze`.
- Bump the version in https://github.com/mitmproxy/mitmproxy/blob/master/mitmproxy/version.py and update https://github.com/mitmproxy/mitmproxy/blob/master/mitmproxy/io_compat.py in the next commit