[pre-commit.ci] auto fixes from pre-commit.com hooks

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Author: pre-commit-ci[bot]

mne/preprocessing/nirs/tests/test_beer_lambert_law.py

@@ -2,7 +2,6 @@
 # License: BSD-3-Clause
 # Copyright the MNE-Python contributors.
 
-import warnings
 
 import numpy as np
 import pytest