Explicitly install some flatpak-builder recommended dependencies

Both elfutils and fuse are "recommended" flatpak-builder dependencies (the latter indirectly via flatpak-builder -> requires flatpak -> recommends xdg-desktop-portal -> requires fuse), but they're needed for some expected core functionality to work. In particular, flatpak-builder needs fuse unless run with --disable-rofiles-fuse, and elfutils is required for debug info to be stripped.

https://phabricator.apertis.org/T8751

Signed-off-by: Ryan Gonzalez ryan.gonzalez@collabora.com