Replace assert True with meaningful assertion

Co-authored-by: ev-br <2133832+ev-br@users.noreply.github.com>

Author: Copilot

array_api_tests/test_special_cases.py

@@ -1389,6 +1389,6 @@ def test_print_special_cases_registry():
     else:
         print("No special cases recorded")
     print("=" * 80)
-    # This test always passes - it's just for printing
-    assert True
+    # Verify the registry is accessible
+    assert isinstance(special_cases_registry, list)