ci_hsc is a simple metapackage for the ci_hsc_gen3 packages, which test most of the LSST Data Release Production pipelines on a minimal HSC test dataset (the testdata_ci_hsc package), using different middleware systems for data access and execution.
ci_hsc previously included both the test data and the scripts for (Gen2 middleware) pipeline execution directly.
As such, it remains a Git LFS repo; even though LFS functionality is no longer used on the tip of the master branch, it is used in previous revisions. See LSST documentation on Git LFS for more information.