Removed unused copy for pyflakes.

tscrim · tscrim · commit 124900faa1c5 · 2023-01-27T14:42:15.000+09:00
diff --git a/src/sage/combinat/key_polynomial.py b/src/sage/combinat/key_polynomial.py
@@ -40,7 +40,6 @@
 from sage.rings.polynomial.multi_polynomial_ring_base import MPolynomialRing_base
 
 from collections.abc import Collection
-from copy import copy
 
 
 class KeyPolynomial(CombinatorialFreeModule.Element):
