dustbowl: move some apps to flatpak

nixos/dustbowl.nix

@@ -238,9 +238,6 @@
     mpv
     zathura
     imv
-    pavucontrol
-    xournalpp
-    libreoffice
     okular
     ungoogled-chromium
     openrgb
@@ -249,7 +246,6 @@
     zotero-beta
     wpa_supplicant_gui
     keepassxc
-    plattenalbum
     spotify
     gnucash
     welle-io
@@ -270,6 +266,8 @@
     (callPackage ./posy-cursor-black.nix { })
   ];
 
+  services.flatpak.enable = true;
+
   services.gnome.gnome-keyring.enable = true;
 
   # Use doas instead of sudo