Flatpak: Remove GLib build

GNOME runtime now includes a recent stable GLib, so no need to build it ourselves anymore.

pkgs/flatpak/com.github.rafostar.Clapper.json

@@ -17,7 +17,6 @@
         "--env=GST_VAAPI_ALL_DRIVERS=1"
     ],
     "modules": [
-        "lib/glib.json",
         "lib/glib-networking.json",
         "shared-modules/gudev/gudev.json",
         "lib/pango.json",

pkgs/flatpak/lib/glib.json

@@ -1,12 +0,0 @@
-{
-    "name": "glib",
-    "buildsystem": "meson",
-    "sources": [
-        {
-            "type": "git",
-            "url": "https://gitlab.gnome.org/GNOME/glib.git",
-            "tag": "2.67.0",
-            "commit": "8f0b968cd128915853d17bf7944f7e0ebd90a399"
-        }
-    ]
-}