Truncate stall output on alg error

The scheduler stall output is intended to help debugging dependency errors - configuration-level problems leading to an impossible CF/DF graph.

However, when an algorithm returns an ERROR state, this can also lead to a "stall," purely because this specific algorithm is not producing its output. Here, the only relevant information is the algorithm(s) that failed, and not the rest of the CF graph.

To reduce log verbosity in production environments (specifically triggering, where algorithm errors may occur without the job aborting), the stall output is truncated when there are algorithms in ERROR state.