You shouldn’t need SLURM to run Rosetta – it should work with any clustering system.
That said, the reason why CSRosetta is suggesting to install SLURM is that there may be some automated scripts in the CSRosetta package which generate SLURM submission scripts for you. If you were to run across any of those scripts, what you’d need to do is take their SLURM file outputs and then re-write them into a format which works with your clustering system.
But that should be relatively easy. The commands being run should be pretty independent of the clustering system in use.