[release-notes] fix number of GTK releases

[Link Dupont <link src gnome org>]

commit 571afa09d868ce04fe2f4be39d60f68260bf6f8c
Author: Link Dupont <link sub-pop net>
Date:   Tue Aug 31 14:32:04 2021 -0400

    fix number of GTK releases

 help/C/developers.page | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/help/C/developers.page b/help/C/developers.page
index 0d307d81..cf335317 100644
--- a/help/C/developers.page
+++ b/help/C/developers.page
@@ -140,12 +140,12 @@
   <section id="gtk4">
     <title>GTK 4</title>
 
-    <p>There have been three minor updates to GTK 4 since the GNOME 40 release:
-    4.2, 4.3, and 4.4. These have included various various enhancements and bug
+    <p>There have been two minor updates to GTK 4 since the GNOME 40 release:
+    4.2, and 4.4. These have included various various enhancements and bug
     fixes:</p>
 
     <list>
-      <item><p>The NGL renderer has continued to see improvements. This includes
+      <item><p>The replacement GL renderer continues to improve. This includes
       speedups, fixes for transformed rendering, avoiding huge intermediate
       textures, and correct handling of partial color fonts.</p></item>
       <item><p>GTK Inspector is now enabled by default, to make debugging