CentOS Stream 10 currently has flatpak-1.15.6. Since we are shipping an unstable Flatpak series in CentOS Stream 10, we should at least try to keep up with the point releases, which means updating to 1.15.7.

This requires updating bubblewrap to 0.9.0.

Corresponding Fedora references:
https://bugzilla.redhat.com/show_bug.cgi?id=2271979
https://src.fedoraproject.org/rpms/flatpak/pull-request/19