chore: update changelog for v1.13.1 release

reeshika-h · reeshika-h · commit bd2acf842aa9 · 2026-08-10T13:08:02.000+05:30
diff --git a/changelog.md b/changelog.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## v1.12.2
+## v1.13.1
 
 ### Aug 17, 2026
 
