swh-indexer: test_add_deadlock fails on Flask 2.2.0
eg. https://forge.softwareheritage.org/harbormaster/unit/30590/
Migrated from T4416 (view on Phabricator)
eg. https://forge.softwareheritage.org/harbormaster/unit/30590/
Migrated from T4416 (view on Phabricator)