The last release of jena-sdb was with Jena 3.17.0 on 2020-12-01.
The code for this module has been removed. Source is available from git with tag “jena-3.17.0”.
The last git commit after 3.17.0 to jena-sdb was fbd27b04e4. This contains changes made in the progress to Jena 4.0.0.
Retired modules can be incorporated back into Jena releases if there is sufficient activity to maintain the code over the long term.