When you delete an artifact definition and all its versions, it is not possible to recreate it with the same name.
The deleted artifact definition still lives in the database but is archived.
You can cleanup the artifacts tables by the SQL statements as listed in:
Make sure you have a valid backup of the database, just as a precaution.
When you delete an artifact, it is archived with no supported way to restore it afterwards. This is something that many customers dislike and enhancement requests have been raised to have this change. Have a look at:
Both ideas are in planned phase which means development has accepted the idea and it will be implemented in a future release.