This MR is updating the libnitrokey package based on the current used version 3.5-3.3 in Debian testing.
I removed the .gitclab-ci.yml from the to folder and added a file debian/pureos-ci.yml as suggested by Guido.
It might be necessary to also pull in the pristine-tar and upstream branch including all the upstream tags (at least the one tag for the imported version upstream/3.5).