This makes us consistent with the default behaviour of GLib, and
its behaviour with G_MESSAGES_DEBUG=all. g_debug() and g_info() are
the two lowest priority levels, and GLib normally silences them by
default.
At the moment, Flatpak uses G_LOG_LEVEL_DEBUG in the flatpak2 domain
as its lowest-priority log level (only shown with flatpak -v -v), and
G_LOG_LEVEL_DEBUG in the flatpak domain as its second-lowest
(shown with flatpak -v or higher). I want to move towards using
G_LOG_LEVEL_INFO for flatpak -v messages, and G_LOG_LEVEL_DEBUG for
flapak -v -v, so that we don't need a second log domain: this is a
policy I've used successfully in Flatpak-derived Steam Runtime code.
This change does not fully implement that policy, but gives us a
migration path towards it, by allowing us to start using g_info() for
flatpak -v messages.
Helps: https://github.com/flatpak/flatpak/issues/5001
Signed-off-by: Simon McVittie <smcv@collabora.com>