gs-updates-page: Slightly improve OS upgrade invalidation

Remove one call to gs_updates_page_invalidate_downloaded_upgrade(), which will remove some spurious invalidations of already-downloaded OS upgrades.

This happens from calls to gs_plugin_status_update(). There are three places where that can be called with GS_PLUGIN_STATUS_INSTALLING or GS_PLUGIN_STATUS_REMOVING: PackageKit, flatpak and rpm-ostree. Installs and removes of flatpaks and rpm-ostrees cannot affect a pending OS update (unless the rpm-ostree change is the OS update itself, but that’s handled already), so we only need to add a notification to the PackageKit code path.

Unfortunately we can’t change the PackageKit plugin to only emit a signal for the GsApp for the actual pending OS upgrade, as that GsApp is created and owned by the fedora-pkgdb-collections plugin rather than the PackageKit plugin. So that means PackageKit has to emit gs_plugin_updates_changed() more generally. This is at least an improvement on before though.

In order to fix this completely, we’d have to merge fedora-pkgdb-collections into the PackageKit plugin. Ideally, by moving it to PackageKit itself and implementing the GetDistroUpgrades method using it. Then gnome-software could (a) have distro upgrade support for all distros supported by PackageKit; and (b) not carry a separate fedora-pkgdb-collections plugin. That’s a lot of work, though, so let’s just nibble this bit off here for now.

Signed-off-by: Philip Withnall pwithnall@endlessos.org