Add changelog entry for #565

Author: sirosen

CHANGELOG.rst

@@ -13,6 +13,8 @@ Unreleased
 - Update vendored schemas: bitbucket-pipelines, circle-ci, compose-spec, dependabot,
   github-workflows, gitlab-ci, mergify, renovate, woodpecker-ci (2025-05-11)
 - Fix: support ``click==8.2.0``
+- Fix a bug in ``Last-Modified`` header parsing which used local time and could
+  result in improper caching. Thanks :user:`fenuks`! (:pr:`565`)
 
 0.33.0
 ------