Consistency in ATAC dimensionality reduction between preprocess and integration yamls

[wlason]

The default value for ATAC dimred in preprocess is LSI, yet the default for ATAC dimred in integration is PCA. Because the pipeline expects PCA but can't find it, it attempts to recalculate PCA for every chosen integration method, which leads to out-of-memory errors on my system even with ~500GB RAM (dataset is ~100k cells). I suggest changing to LSI in integration.