Only test sparse for Py3.10+.

Author: hameerabbasi

tests/_helpers.py

@@ -1,4 +1,5 @@
 from importlib import import_module
+import sys
 
 import pytest
 
@@ -8,6 +9,10 @@
 if np.__version__[0] == '1':
     wrapped_libraries.append("numpy")
 
+# `sparse` added array API support as of Python 3.10.
+if sys.version_info >= (3, 10):
+    all_libraries.append('sparse')
+
 def import_(library, wrapper=False):
     if library == 'cupy':
         pytest.importorskip(library)