[gnome-build-meta/matthiasc/3.38.4] Switch gtkmm to meson

[Matthias Clasen <matthiasc src gnome org>]

commit 6377c9b0787fd5b6c663e5808caf7b3dce2334de
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Feb 16 16:33:41 2021 -0500

    Switch gtkmm to meson
    
    the autotools build seems to have decayed.

 elements/core-deps/gtkmm-3.bst | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)
---
diff --git a/elements/core-deps/gtkmm-3.bst b/elements/core-deps/gtkmm-3.bst
index e04eb768..f8538491 100644
--- a/elements/core-deps/gtkmm-3.bst
+++ b/elements/core-deps/gtkmm-3.bst
@@ -1,11 +1,12 @@
-kind: autotools
+kind: meson
 sources:
 - kind: tar
   url: gnome_downloads:gtkmm/3.24/gtkmm-3.24.3.tar.xz
   ref: 60497c4f7f354c3bd2557485f0254f8b7b4cf4bebc9fee0be26a77744eacd435
 build-depends:
 - freedesktop-sdk.bst:components/perl-xml-parser.bst
-- freedesktop-sdk.bst:public-stacks/buildsystem-autotools.bst
+- freedesktop-sdk.bst:public-stacks/buildsystem-meson.bst
+
 depends:
 - core-deps/atkmm-1.6.bst
 - core-deps/cairomm-1.0.bst
@@ -13,6 +14,3 @@ depends:
 - sdk/glib.bst
 - sdk/gtk+-3.bst
 - freedesktop-sdk.bst:bootstrap-import.bst
-variables:
-  conf-local: >-
-    --enable-maintainer-mode