Revert "Fix unused snapshots not triggering failure in CI"

[frenck]

Reverts #128162

Comment by @jbouwh here: #128162 (comment)

This fix seems to cause a performance regression as a side effect.

E.g.: pytest -n auto tests/components/mqtt/

This takes 25.75 sec without this fix on my dev env. and 72.24 sec with.

When coverage is tested too, it gets worse: This takes 46.24 sec without this fix and 189.09 sec with.

[jbouwh]

Thanks @frenck and @epenet 👍