Issue #13809: Make bz2 module work with threads disabled.

Original patch by Amaury Forgeot d'Arc.
diff --git a/Misc/NEWS b/Misc/NEWS
index 8178a92..246b3c1 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -447,6 +447,9 @@
 Library
 -------
 
+- Issue #13809: Fix regression where bz2 module wouldn't work when threads are
+  disabled. Original patch by Amaury Forgeot d'Arc.
+
 - Issue #13589: Fix some serialization primitives in the aifc module.
   Patch by Oleg Plakhotnyuk.