[gnome-builder] flatpak: remove preferences addin

[Christian Hergert <chergert src gnome org>]

commit f7e672d00b5f3bb6ffc8fb810df3557ce67ce582
Author: Christian Hergert <chergert redhat com>
Date:   Fri Apr 30 15:18:03 2021 -0700

    flatpak: remove preferences addin
    
    This wans't getting used much at all and creates considerable complexity
    as we go forward into a world where the Flatpak integration is tied into
    the project context that has loaded (so a gnome-builder-flatpak per
    project like we do for git/clang/etc).

 src/plugins/flatpak/flatpak-plugin.c               |   4 -
 .../flatpak/gbp-flatpak-preferences-addin.c        | 470 ---------------------
 .../flatpak/gbp-flatpak-preferences-addin.h        |  31 --
 src/plugins/flatpak/meson.build                    |   1 -
 4 files changed, 506 deletions(-)
---
diff --git a/src/plugins/flatpak/flatpak-plugin.c b/src/plugins/flatpak/flatpak-plugin.c
index 4f5a47163..5c9ef237f 100644
--- a/src/plugins/flatpak/flatpak-plugin.c
+++ b/src/plugins/flatpak/flatpak-plugin.c
@@ -33,7 +33,6 @@
 #include "gbp-flatpak-config-provider.h"
 #include "gbp-flatpak-dependency-updater.h"
 #include "gbp-flatpak-pipeline-addin.h"
-#include "gbp-flatpak-preferences-addin.h"
 #include "gbp-flatpak-runtime-provider.h"
 #include "gbp-flatpak-workbench-addin.h"
 
@@ -63,9 +62,6 @@ _gbp_flatpak_register_types (PeasObjectModule *module)
   peas_object_module_register_extension_type (module,
                                               IDE_TYPE_PIPELINE_ADDIN,
                                               GBP_TYPE_FLATPAK_PIPELINE_ADDIN);
-  peas_object_module_register_extension_type (module,
-                                              IDE_TYPE_PREFERENCES_ADDIN,
-                                              GBP_TYPE_FLATPAK_PREFERENCES_ADDIN);
   peas_object_module_register_extension_type (module,
                                               IDE_TYPE_WORKBENCH_ADDIN,
                                               GBP_TYPE_FLATPAK_WORKBENCH_ADDIN);
diff --git a/src/plugins/flatpak/meson.build b/src/plugins/flatpak/meson.build
index d357a776f..e885c22cc 100644
--- a/src/plugins/flatpak/meson.build
+++ b/src/plugins/flatpak/meson.build
@@ -28,7 +28,6 @@ plugins_sources += files([
   'gbp-flatpak-install-dialog.c',
   'gbp-flatpak-manifest.c',
   'gbp-flatpak-pipeline-addin.c',
-  'gbp-flatpak-preferences-addin.c',
   'gbp-flatpak-runner.c',
   'gbp-flatpak-runtime-provider.c',
   'gbp-flatpak-runtime.c',