chore: fix tests that rely on split route snapshots (#2224)

* chore: fix tests that rely on split route snapshots

* chore: clearer test message

* chore: add snapshot with updated test message

* chore: disable NEXT_SPLIT_API_ROUTES env var for test + remove console.log

* chore: spread process.env to avoid mutation

* chore: correctly disable NEXT_SPLIT_API_ROUTES + update snapshot

Author: MarcL