flake: TestCollectInsights error log dropped

Seen on: https://github.com/coder/coder/runs/23674923557

```
    t.go:108: 2024-04-10 18:22:29.578 [erro]  coderd.metrics_cache: refresh  error="sql: no rows in result set"
         *** slogtest: log detected at level ERROR; TEST FAILURE ***
```