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

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

tests/test_virtual_functions.py

@@ -270,7 +270,7 @@ def __call__(self, first, second, visitor):
             # lambda is a workaround, which adds extra frame to the
             # current CPython thread. Removing lambda reveals the bug
             # [https://github.com/pybind/pybind11/issues/3357]
-            (lambda : visitor(Data(first.value + second.value)))()
+            (lambda: visitor(Data(first.value + second.value)))()
 
     class StoreResultVisitor:
         def __init__(self):