Bump version and update changelog

Author: lafrech

CHANGELOG.rst

@@ -2,6 +2,14 @@ Changelog
 =========
 
 
+4.2.1 (2026-01-23)
+------------------
+
+Bug fixes:
+
+- Fix validation of URLs beginning with uppercare `FILE` (:issue:`2891`).
+  Thanks :user:`thanhlecongg` for reporting and fixing.
+
 4.2.0 (2026-01-04)
 ------------------
 

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "marshmallow"
-version = "4.2.0"
+version = "4.2.1"
 description = "A lightweight library for converting complex datatypes to and from native Python datatypes."
 readme = "README.rst"
 license = { file = "LICENSE" }