Refs: * https://github.com/pypa/gh-action-pypi-publish/issues/107
This patch adds constraint files with the dependency tree generated by `pip-compile` under Python 3.9. They are now integrated into the action container image. Refs: * https://github.com/pypa/gh-action-pypi-publish/issues/101 * https://github.com/pypa/gh-action-pypi-publish/issues/107