Speed up test_sorting_s3_nwb_zarr (again) (#4538)

Author: chrishalcrow

src/spikeinterface/extractors/tests/test_nwbextractors_streaming.py

@@ -224,8 +224,14 @@ def test_sorting_s3_nwb_zarr(tmp_path):
     # just take 3 random units to test
     rng = np.random.default_rng(seed=2205)
     three_unit_ids = rng.choice(sorting.unit_ids, size=3)
-    sorting_sub = sorting.select_units(unit_ids=three_unit_ids)
-    sorting_loaded_sub = sorting_loaded.select_units(unit_ids=three_unit_ids)
+
+    first_spike_sample_index = 21864115
+    sorting_sub = sorting.select_units(unit_ids=three_unit_ids).frame_slice(
+        start_frame=first_spike_sample_index, end_frame=first_spike_sample_index + 10_000
+    )
+    sorting_loaded_sub = sorting_loaded.select_units(unit_ids=three_unit_ids).frame_slice(
+        start_frame=first_spike_sample_index, end_frame=first_spike_sample_index + 10_000
+    )
 
     check_sortings_equal(sorting_sub, sorting_loaded_sub)