[5.0.x] Added stub release notes and release date for 5.0.9 and 4.2.16.

Backport of 67efd42 from main.

Author: nessita

docs/releases/4.2.16.txt

@@ -0,0 +1,10 @@
+===========================
+Django 4.2.16 release notes
+===========================
+
+*September 3, 2024*
+
+Django 4.2.16 fixes one security issue with severity "moderate" and one
+security issues with severity "low" in 4.2.15.
+
+...

docs/releases/5.0.9.txt

@@ -0,0 +1,10 @@
+===========================
+Django 5.0.9 release notes
+===========================
+
+*September 3, 2024*
+
+Django 5.0.9 fixes one security issue with severity "moderate" and one security
+issues with severity "low" in 5.0.8.
+
+...

docs/releases/index.txt

@@ -25,6 +25,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   5.0.9
    5.0.8
    5.0.7
    5.0.6
@@ -41,6 +42,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   4.2.16
    4.2.15
    4.2.14
    4.2.13