Add CHANGELOG entry

Signed-off-by: Facundo Tuesca <facundo.tuesca@trailofbits.com>

Author: facutuesca

CHANGELOG.rst

@@ -89,6 +89,8 @@ Changelog
   method for computing hashes.
 * Added :doc:`/hazmat/primitives/hpke` support implementing :rfc:`9180` for
   hybrid authenticated encryption.
+* Added new :doc:`/hazmat/primitives/asymmetric/mldsa` module with
+  support for ML-DSA-65 signing and verification with the AWS-LC backend.
 
 .. _v46-0-6: