Remove the use of Notification hole

[A6GibKm]

Starting with libnotify 0.8, all calls go through the portal.

[flathubbot]

Started test build 30965

[flathubbot]

Build 30965 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/13614/org.gnome.Rhythmbox3.flatpakref

[hadess]

Starting with libnotify 0.8, all calls go through the portal.

Which version ships with the runtime we use, and which version of xdg-desktop-portal does this require?

[A6GibKm]

libnotify 0.8.2 https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/44/elements/sdk/libnotify.bst

and whichever version of xdg-desktop-portal introduced the notifications portal.

[hadess]

libnotify 0.8.2 https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/44/elements/sdk/libnotify.bst

Please put this information in the commit message.

and whichever version of xdg-desktop-portal introduced the notifications portal.

Please find the precise version and add it to commit message to show that some research was done to make sure we didn't cut off a number of users for whom notifications worked before.

[A6GibKm]

Done.

[flathubbot]

Started test build 31183

[hadess]

Done.

Please remove the periods at the end of the URLs, and we should be good to go.

[flathubbot]

Build 31183 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/13832/org.gnome.Rhythmbox3.flatpakref

[A6GibKm]

Done.

[flathubbot]

Started test build 31187

[flathubbot]

Build 31187 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/13836/org.gnome.Rhythmbox3.flatpakref

[hadess]

Unfortunately it throws warnings and messages:

(rhythmbox:2): libnotify-WARNING **: 15:02:43.424: Running in confined mode, using Portal notifications. Some features and hints won't be supported
libnotify-Message: 15:02:43.424: Category is not available when using Portal Notifications
libnotify-Message: 15:02:43.425: Category is not available when using Portal Notifications
libnotify-Message: 15:02:43.454: Category is not available when using Portal Notifications

Those should be fixed before we can merge this patch.

[flathubbot]

Started test build 96936

[flathubbot]

Build 96936 failed

[flathubbot]

Started test build 97009

[flathubbot]

Build 97009 failed

[flathubbot]

Started test build 97013

[flathubbot]

Build 97013 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/79776/org.gnome.Rhythmbox3.flatpakref