Test on Python 3.13 beta releases (#1107)

* Test on Python 3.13 beta releases

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

Author: akx

.github/workflows/ci.yml

@@ -35,6 +35,7 @@ jobs:
           - "3.11"
           - "3.12"
           - "pypy3.10"
+          - "3.13-dev"
     env:
       BABEL_CLDR_NO_DOWNLOAD_PROGRESS: "1"
       BABEL_CLDR_QUIET: "1"