Fix red develop dfbb35a85300

The merge lane found `develop` red at `dfbb35a853003193e87f057ab1707f7d7a0dfa30` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `tests/test_credentials_connection_test.py::test_app_token_field_is_declared_but_no_row_ever_serializes_its_value` - `api-unit-dc-test` The whole gate log: artifact `14618` on lane task 12904. Make `develop` pass its full gate again. Open a PR as usual: the merge lane merges a PR that fixes some of these and adds no failure even while `develop` is red.

Already fixed on develop by PR #7790 (aaee978f1f). The credentials test file passes there: 102 passed. No PR needed. Memory: none applied.