[dia] swig: drop unused swig based bindings

[Zander Brown <zbrown src gnome org>]

commit 8262367e6f0e3b0a062a8a070055e3207671ab99
Author: Zander Brown <zbrown gnome org>
Date:   Fri Oct 16 00:58:35 2020 +0100

    swig: drop unused swig based bindings

 bindings/.gitignore           |   5 -
 bindings/Doxyfile             |  26 ---
 bindings/dia-bindings.h       |  18 --
 bindings/dia-connections.cpp  | 117 ----------
 bindings/dia-connections.h    | 106 ---------
 bindings/dia-diagramdata.cpp  | 177 --------------
 bindings/dia-diagramdata.h    | 131 -----------
 bindings/dia-extra.cpp        |  81 -------
 bindings/dia-extra.h          |  17 --
 bindings/dia-object.cpp       | 234 -------------------
 bindings/dia-object.h         | 113 ---------
 bindings/dia-properties.cpp   | 529 ------------------------------------------
 bindings/dia-properties.h     | 224 ------------------
 bindings/dia-python-extra.cpp | 125 ----------
 bindings/dia-python-extra.h   |  18 --
 bindings/dia-renderer.cpp     | 249 --------------------
 bindings/dia-renderer.h       | 157 -------------
 bindings/dia.swig             | 396 -------------------------------
 bindings/test.py              | 164 -------------
 meson.build                   |   2 +-
 20 files changed, 1 insertion(+), 2888 deletions(-)
---
diff --git a/meson.build b/meson.build
index 9dd518218..94a97bcf2 100644
--- a/meson.build
+++ b/meson.build
@@ -83,7 +83,7 @@ add_project_arguments([
   '-DGLIB_VERSION_MAX_ALLOWED=@0@'.format(glib_ver),
   '-DGSEAL_ENABLE',
   '-DGTK_DISABLE_DEPRECATED',
-], language: 'c')
+], language: ['c', 'cpp'])
 
 
 global_c_args = []