fix: add type annotation to tol

Author: Alvaro-Kothe

pandas/core/nanops.py

@@ -1608,7 +1608,7 @@ def check_below_min_count(
     return False
 
 
-def _zero_out_fperr(arg, tol):
+def _zero_out_fperr(arg, tol: float | np.ndarray):
     # #18044 reference this behavior to fix rolling skew/kurt issue
     if isinstance(arg, np.ndarray):
         return np.where(np.abs(arg) < tol, 0, arg)