This raises the versions of bundled software, providing e.g.
autoconf 2.71, which is needed for Python 3.12.
As the releases are built (without a surrounding extra container)
on GitHub Actions these days, we don't need to hold the docker
images back to an old version for the sake of compatibility;
instead, updating to a newer version provides more modern tools
for users of the docker image.
Martin Storsjö