Prepare changelog for release

```
./scripts/assemble_changelog.py
```

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog b/ChangeLog
index 9b30aff..6f7c86c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 Mbed TLS ChangeLog (Sorted per branch, date)
 
+= Mbed TLS x.x.x branch released xxxx-xx-xx
+
+Bugfix
+   * Fix builds on Windows with clang
+
+Changes
+   * Update test data to avoid failures of unit tests after 2023-08-07.
+
 = Mbed TLS 3.4.0 branch released 2023-03-28
 
 Default behavior changes