Added stub release notes for 4.2.9.

docs/releases/4.2.9.txt

@@ -0,0 +1,12 @@
+==========================
+Django 4.2.9 release notes
+==========================
+
+*Expected January 2, 2024*
+
+Django 4.2.9 fixes a bug in 4.2.8.
+
+Bugfixes
+========
+
+* ...

docs/releases/index.txt

@@ -41,6 +41,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   4.2.9
    4.2.8
    4.2.7
    4.2.6