tests: Don't check the number of created 'person' objects
They are an implementation detail of storage backends; and get_stats() will stop returning the 'person' count in the next version of swh-storage-core.
Fixes build [1]
- [1] https://jenkins.softwareheritage.org/job/DLDSVN/job/tests/820/console
- [2] https://jenkins.softwareheritage.org/job/DENV/job/tests/lastBuild/console
Similar to swh-loader-git!126 (closed)
Test Plan
tox
Migrated from D3985 (view on Phabricator)