contrib: add a bat file to build all of the wheels on Windows This is duplicated from the current CI config, to be able to build releases consistently outside of CI. I don't like the duplication, but I'm not worried about things changing too often, so I'm not bothering with PowerShell or some form that would allow execution by the CI runner. We should consider putting the config in `pyproject.toml`, where things like what python versions to support can be centrally controlled for all platforms. The output directory is different from CI here, but that's fine because it is intended to run this on a system that is *not* hosting the CI setup, and `dist/` is more standard. I dropped the `win32` part of the output because that implies the 32-bit Intel architecture. Apparently, arm64 builds are supported back to Python 3.9, but support is still experimental (with py3.13)[1]. The CI system starts arm64 support with Python 3.11, because that's the first version that an arm64 Python installer was available on Windows. This doesn't second guess that decision. The required `msgfmt.exe` was installed manually[2], as it isn't currently handled by the dependency installation script. Otherwise, this was successfully used with an activated venv based on Python 3.12.5, and only `cibuildwheel==2.21.3` installed. [1] https://cibuildwheel.pypa.io/en/stable/#what-does-it-do [2] https://github.com/mlocati/gettext-iconv-windows/releases/download/v0.22.5a-v1.17-r3/gettext0.22.5a-iconv1.17-shared-64.exe