The "Check if generated files are up to date" job of GitHub Actions
now runs the "autoreconf -ivf -Werror" command instead of the "make
regen-configure" command to avoid depending on the external quay.io
server.
Add Tools/build/regen-configure.sh script to regenerate the configure
with an Ubuntu container image. The
"quay.io/tiran/cpython_autoconf:271" container image
(https://github.com/tiran/cpython_autoconf) is no longer used.
Victor Stinner