F-Droid can't build

[licaon-kter]

ref: https://gitlab.com/fdroid/fdroiddata/-/jobs/5066442847#L460

ref: https://github.com/NathanielMotus/UmlClassEditor/pull/5/files

Ping @RickyM7

/LE: fyi https://gitlab.com/fdroid/fdroiddata/-/commit/726267bc9110d41fef03460b401242d55d673e59