bug#22628: Emacs: ^ in installed package list misses some upgrades

[Ludovic Courtès]

Hello!

In current Guix master we have Texinfo 6.0 and 6.1.  With 6.0 installed
in my profile, hitting ^ in the M-x guix-installed-packages buffer does
not mark Texinfo as a candidate for upgrade.

Ludo’.