[devhelp] Bump version to 40.alpha

[Sébastien Wilmet <swilmet src gnome org>]

commit 954395c7d4f139d7d725f2c0f11aa78783794c80
Author: Sébastien Wilmet <sw swilmet be>
Date:   Fri Jan 1 07:20:29 2021 +0100

    Bump version to 40.alpha
    
    I've checked, everywhere the version string is used, it should still
    work fine even though it contains letters now.

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 2e80179a..bdd55b2d 100644
--- a/meson.build
+++ b/meson.build
@@ -6,7 +6,7 @@
 project(
   'devhelp', 'c',
   meson_version: '>= 0.53',
-  version: '3.38.1',
+  version: '40.alpha',
   default_options: ['warning_level=2']
 )