Merging core-updates

[Ludovic Courtès]

Hello Guix!

‘core-updates’ seems to be in a rather good shape.  Unfortunately, the
web UI and APIs of hydra.gnu.org and berlin.guixsd.org make it difficult
to have a clear view of the situation.

“make assert-binaries-available” passes for all architectures, meaning
we have Emacs/X11 among other things available as substitutes.

The ‘bootstrap-tarballs’ package is available on all platforms including
aarch64.

On x86_64, LibreOffice, IceCat, etc. are available as substitutes; ‘guix
weather’ reports only 50% of coverage on berlin and 80% on
mirror.hydra.gnu.org (we’ll have to elucidate the bad number on berlin.)
I’m using ‘core-updates’ for both my system and my user profile.

Overall I’m in favor of merging.

What do people think?

Thanks,
Ludo’.