[libpanel] build: include vapidir in search path

[Christian Hergert <chergert src gnome org>]

commit 7cbb4e1e5c7f7c6066feedffd74f5e1aa1a02261
Author: Christian Hergert <christian hergert me>
Date:   Wed Sep 14 14:11:13 2022 -0700

    build: include vapidir in search path
    
    So that we actually find what we are looking for on some systems,
    including macOS which might have vapigen from brew.

 src/meson.build | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/src/meson.build b/src/meson.build
index 4884b3a..9be5802 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -195,10 +195,8 @@ if generate_gir
           sources: libpanel_gir.get(0),
           install: true,
       install_dir: vapidir,
-         packages: [ 'gio-2.0',
-                     'gtk4',
-                     'libadwaita-1'
-                   ],
+         packages: [ 'gio-2.0', 'gtk4', 'libadwaita-1' ],
+        vapi_dirs: [vapidir],
     )
   endif
 endif