Fix failing /sync tests

They should be passing but for some reason are not.

Sytests:

    × Newly joined room has correct timeline in incremental sync
    × Newly joined room includes presence in incremental sync
    × When user joins a room the state is included in the next sync
    × When user joins a room the state is included in a gapped sync
    × When user joins and leaves a room in the same batch, the full state is still included in the next sync
    × Current state appears in timeline in private history with many messages after