fix import order in test case (#624)

Fixes one issue reported by the linter on `branch-23.12`

Authors:
  - Gregory Lee (https://github.com/grlee77)

Approvers:
  - Gigon Bae (https://github.com/gigony)
  - https://github.com/jakirkham

URL: #624

python/cucim/tests/performance/clara/test_read_region_memory_usage.py

@@ -102,9 +102,10 @@ def test_tiff_iterator(testimg_tiff_stripe_4096x4096_256):
     See issue gh-598: https://github.com/rapidsai/cucim/issues/598
     """
 
-    import numpy as np
-    import random
     import os
+    import random
+
+    import numpy as np
     import psutil
 
     slide_path = testimg_tiff_stripe_4096x4096_256