[gnome-todo] Revert "flatpak: Also build GTK4"

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit fb7c216b0613b1341c96f90f63882eaabddca84b
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed May 6 13:48:25 2020 -0300

    Revert "flatpak: Also build GTK4"
    
    This reverts commit 200d1baaa3bf084c9fbbdd87f5856bc5e004a1c7. Nope.

 build-aux/flatpak/org.gnome.Todo.json | 47 -----------------------------------
 1 file changed, 47 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Todo.json b/build-aux/flatpak/org.gnome.Todo.json
index 599f940..b19db31 100644
--- a/build-aux/flatpak/org.gnome.Todo.json
+++ b/build-aux/flatpak/org.gnome.Todo.json
@@ -157,53 +157,6 @@
                 }
             ]
         },
-        {
-            "name" : "libsass",
-            "buildsystem" : "meson",
-            "builddir" : true,
-            "config-opts": [
-                "--libdir=/app/lib"
-            ],
-            "sources" : [
-                {
-                    "type" : "git",
-                    "url" : "https://github.com/lazka/libsass.git";,
-                    "branch" : "meson"
-                }
-            ]
-        },
-        {
-            "name" : "sassc",
-            "buildsystem" : "meson",
-            "builddir" : true,
-            "config-opts": [
-                "--libdir=/app/lib"
-            ],
-            "sources" : [
-                {
-                    "type" : "git",
-                    "url" : "https://github.com/lazka/sassc.git";,
-                    "branch" : "meson"
-                }
-            ]
-        },
-        {
-            "name": "gtk",
-            "buildsystem": "meson",
-            "builddir": true,
-            "config-opts": [
-                "-Ddemos=false",
-                "-Dbuild-examples=false",
-                "-Dbuild-tests=false",
-                "--libdir=/app/lib"
-            ],
-            "sources": [
-                {
-                    "type": "git",
-                    "url": "https://gitlab.gnome.org/GNOME/gtk.git";
-                }
-            ]
-        },
         {
             "name" : "gnome-todo",
             "buildsystem" : "meson",