A name bound twice keeps only the second binding. In `tests/` that is nearly
always a repeated import, harmless but misleading, and the same rule is what
catches the cases that are not harmless: a local that shadows an import the
module still calls, and a second `def test_x` that quietly replaces the first.
311 of the 344 sites were repeated imports and came out with ruff's own fix.
The remaining 33 needed a decision. Four modules imported a name they never
used because a local definition below already shadowed it. Two comprehensions
bound `call` over `unittest.mock.call`, which those modules import and use.
One test rebound the two module handles its nested reload closure had captured.
One class attribute shadowed an unused `status` import.
The load-test fixtures move to a conftest, which is how pytest is meant to share
them, so the test module no longer imports three fixture names it never calls.
The nine `prisma_client` parameters keep a narrow `noqa`: pytest resolves that
fixture by name before the body runs, so the parameter never shadows anything.
- test_caching_router: Use REDIS_HOST/PORT/PASSWORD/SSL instead of
non-existent REDIS_HOST_2 variants
- test_router_init_azure_service_principal: Use monkeypatch.setenv instead
of patching the os module in only one file, so both common_utils._resolve_env_var
and get_azure_ad_token_provider see the mocked credentials. Also clear
AZURE_OPENAI_API_KEY to prevent it from short-circuiting the token provider path.
