The new repositories are signed by a different signing key (our team's
standard key [2] instead of a key generated by Cloudsmith), so we
cannot set up redirects.
ppa1 and ppa2 will be shut down on or shortly after Nov 1, 2025.
Because only about 15% of apt clients have migrated to the new repos,
we will shut down ppa1 and ppa2 for an hour a day every four weeks,
starting *today*, to attract the attention of human operators.