Draft: Cherry-pick patches to support Unicode 16
This enables the gnome-characters update from https://gitlab.gnome.org/GNOME/gnome-characters/-/merge_requests/133 to work.
I'm going to ask upstream if they are comfortable cherry-picking this to 2.82. Even if they don't, I believe we want this.
@smcv Do you need glib 2.82.2-3 to migrate to Testing before I upload this? glib won't be able to migrate until https://bugs.debian.org/1087778 is fixed in a separate package.