CI/BENCH: Add style checks for benchmarks

Author: Kai-Striega

.github/workflows/lint.yml

@@ -49,5 +49,5 @@ jobs:
         poetry run ruff version
         # Check the source file, ignore type annotations (ANN) for now.
         poetry run ruff check numpy_financial/ --ignore F403 --select E,F,B,I
-        # Check the test file
-        poetry run ruff check tests/ --select E,F,B,I
+        # Check the test and benchmark files
+        poetry run ruff check tests/ benchmarks/ --select E,F,B,I

benchmarks/benchmarks.py

@@ -1,4 +1,5 @@
 import numpy as np
+
 import numpy_financial as npf