[gnome-builder] flatpak: Drop amtk dependency

[Christian Hergert <chergert src gnome org>]

commit 473eac65964a83e8b370acab6a6128e4a1ab190d
Author: vanadiae <vanadiae35 gmail com>
Date:   Mon Jul 12 23:12:27 2021 +0200

    flatpak: Drop amtk dependency
    
    It is no longer needed for devhelp.

 build-aux/flatpak/org.gnome.Builder.json | 12 ------------
 1 file changed, 12 deletions(-)
---
diff --git a/build-aux/flatpak/org.gnome.Builder.json b/build-aux/flatpak/org.gnome.Builder.json
index ebbf88998..2bb2c1412 100644
--- a/build-aux/flatpak/org.gnome.Builder.json
+++ b/build-aux/flatpak/org.gnome.Builder.json
@@ -292,18 +292,6 @@
                 }
             ]
         },
-        {
-            "name" : "amtk",
-            "buildsystem" : "autotools",
-            "builddir" : true,
-            "sources" : [
-                {
-                    "type" : "archive",
-                    "url" : "https://download.gnome.org/sources/amtk/5.0/amtk-5.0.0.tar.xz";,
-                    "sha256" : "12a996978a30b7b69a810ac0c5656d5cf2f58d9787b98a0c028ff1b64e8f31ff"
-                }
-            ]
-        },
         {
             "name" : "devhelp",
             "buildsystem" : "meson",