[5.0.x] Added stub release notes for 4.2.7.

Backport of 034457941abf33b194cb145443575bf7fb454faf from main

docs/releases/4.2.7.txt

@@ -0,0 +1,12 @@
+==========================
+Django 4.2.7 release notes
+==========================
+
+*Expected November 1, 2023*
+
+Django 4.2.7 fixes several bugs in 4.2.6.
+
+Bugfixes
+========
+
+...

docs/releases/index.txt

@@ -33,6 +33,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   4.2.7
    4.2.6
    4.2.5
    4.2.4