remove version from workspace again, this fixes prepare_release.py

[github-actions[bot]]

Please complete the following tasks before merging this PR:

• [x] update dependencies (cargo update + check cargo outdated)
• [x] update zugkontrolle-macros/lizenzen folder
  • clean current licenses
  • run fetch_licenses.py
  • check if everything still compiles (e.g. .gitkeep-files for fonts were not deleted)
  • commit result
• [x] update Changelog.md, so all included changes appear under the section
• [x] update zugkontrolle.desktop