[libadwaita/wip/exalm/subproject] meson: Don't add dist script for subprojects

[Alexander Mikhaylenko <alexm src gnome org>]

commit b680f8d9daea4f3f594365ee6a3af3db6884d59f
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sat Apr 23 01:39:54 2022 +0400

    meson: Don't add dist script for subprojects
    
    Not sure why meson can't figure this out itself, but whatever.
    
    See https://gitlab.gnome.org/GNOME/libhandy/-/issues/463

 meson.build | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index ae0de69c..65cca257 100644
--- a/meson.build
+++ b/meson.build
@@ -145,7 +145,9 @@ configure_file(
          output: 'run',
   configuration: run_data)
 
-meson.add_dist_script('build-aux'/ 'meson'/ 'dist-data.py')
+if not meson.is_subproject()
+    meson.add_dist_script('build-aux'/ 'meson'/ 'dist-data.py')
+endif
 
 summary(
   {