Update for snakemake 8

[rabdill]

JJ pointed out that the --slurm stuff is deprecated or gone now, these instructions aren't good after v7

• https://bluegenes.github.io/Using-Snakemake_Profiles/
• https://snakemake.readthedocs.io/en/stable/snakefiles/configuration.html#cluster-configuration-not-supported-anymore
• Old: https://snakemake.readthedocs.io/en/v7.19.1/executing/cluster.html