Cleanup test logging

[CHr15F0x]

TL;DR
We should be fine with test_log only.

---

We're currently using:
test_log
and/or

let _ = env_logger::builder().is_test(true).try_init();

( ⬆️ which is redundant with test_log)
or

    let _ = tracing_subscriber::fmt()
        .with_env_filter(EnvFilter::from_default_env())
        .try_init();