Fix relative import for remove_small_instances in decoders

The function lives in connectomics.decoding.utils, not
connectomics.decoding.decoders.utils, so the import needs
to go up one package level (..utils instead of .utils).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Donglai Wei

connectomics/decoding/decoders/segmentation.py

@@ -236,7 +236,7 @@ def decode_instance_binary_contour_distance(
 
     # Remove small instances if min_instance_size is specified
     if min_instance_size > 0:
-        from .utils import remove_small_instances
+        from ..utils import remove_small_instances
         segmentation = remove_small_instances(segmentation, thres_small=min_instance_size, mode='background')
 
     if return_seed:
@@ -529,7 +529,7 @@ def decode_distance_watershed(
 
     # Remove small instances if min_instance_size is specified
     if min_instance_size > 0:
-        from .utils import remove_small_instances
+        from ..utils import remove_small_instances
         segmentation = remove_small_instances(
             segmentation,
             thres_small=min_instance_size,