Only apply include labels filter if include_labels not empty (#827)

* dont skip unit if include_labels list is empty

* update check for np array size

src/spyglass/spikesorting/analysis/v1/group.py

@@ -96,9 +96,10 @@ def filter_units(
         for ind, unit_labels in enumerate(labels):
             if isinstance(unit_labels, str):
                 unit_labels = [unit_labels]
-            if np.all(~np.isin(unit_labels, include_labels)) or np.any(
-                np.isin(unit_labels, exclude_labels)
-            ):
+            if (
+                include_labels.size > 0
+                and np.all(~np.isin(unit_labels, include_labels))
+            ) or np.any(np.isin(unit_labels, exclude_labels)):
                 # if the unit does not have any of the include labels
                 # or has any of the exclude labels, skip
                 continue