[gimp] meson: update the end WARNING about meson being experimental.

[Jehan <jehanp src gnome org>]

commit a791151ed05b6e2f7b0ecb71db8be9629d61f5df
Author: Jehan <jehan girinstud io>
Date:   Wed Aug 31 01:39:12 2022 +0200

    meson: update the end WARNING about meson being experimental.
    
    Now we call it "extensive testing phase" and encourage packagers to use
    meson and report bugs.

 meson.build | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/meson.build b/meson.build
index 5be4c6644e..6a19df48a1 100644
--- a/meson.build
+++ b/meson.build
@@ -1868,10 +1868,9 @@ endif
 if not platform_windows
   warning('''
 
-          MESON BUILD IS STILL EXPERIMENTAL!
+          MESON BUILD IS IN EXTENSIVE TESTING PHASE!
 
-          we encourage usage of meson if you want to test and
-          report bugs. Yet if you are a packager, DO NOT USE
-          meson until we fix all known issues and bugs.
+          we now encourage usage of meson for packagers.
+          Please build GIMP with meson and report bugs.
           ''')
 endif