build(deps): bump berkeleydb from 18.1.5 to 18.1.6 (RDFLib#2388)

Bumps [berkeleydb](https://www.jcea.es/programacion/pybsddb.htm) from 18.1.5 to 18.1.6.

---
updated-dependencies:
- dependency-name: berkeleydb
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]