compile_parallel.py: correctly handle incomplete proofs
compile_parallel.py: correctly handle incomplete proofs

If the proof we sent to the worker does not fully solve all subgoals,
raise an error instead of waiting forever / for a timeout.

mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl