Fix DeprecationWarning

(cherry picked from commit b8b0cee)

nvpair.pxi

@@ -9,12 +9,7 @@ from types cimport *
 from libc.stdint cimport uintptr_t
 from libc.stdlib cimport malloc, free
 
-try:
-    from collections import Sequence
-except ImportError:
-    # >= py3.10 moved everything into top-level "abc" module
-    # https://docs.python.org/3.9/library/collections.html
-    from collections.abc import Sequence
+from collections.abc import Sequence
 
 
 @cython.internal