build: release 1.3.21

- Bump the version to 1.3.21 and close the Unreleased section of the
  changelog as 1.3.21.

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file.
 
-## [Unreleased]
+## [1.3.21] - 2026-11-13
 
 ### Changed
 - Built access level labels from their bits instead of a fixed table of combinations, so a level the server adds later is labelled too. A project level (bit 16 and up) is named after the project as the server reports it to its members, e.g. `Brain/MINDS 2.0 Open`, and otherwise `Project<n> Open`. A restrict network other than CBS is `Restrict<n> Open`; `0x0200`, formerly `5Kikan Open`, is now `Restrict2 Open`.

pyproject.toml

@@ -7,7 +7,7 @@ name = "mdrsclient"
 
 [project]
 name = "mdrs-client-python"
-version = "1.3.20"
+version = "1.3.21"
 description = "The mdrs-client-python is python library and a command-line client for up- and downloading files to and from MDRS based repository."
 authors = [
     { name = "Yoshihiro OKUMURA", email = "yoshihiro.okumura@riken.jp" }