On NextSeq runs, we're always parsing the SampleSheet from the top-level directory:
https://github.com/BCCDC-PHL/symlink-illumina-fastq-by-project-id/blob/38f06d4384246e6009ca59203d5e806911649952/symlink_illumina_fastq_by_project_id.py#L255
...but we should be parsing the SampleSheet from the Analysis/<LATEST>/Data
directory.