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

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

lib/iris/common/metadata.py

@@ -70,7 +70,9 @@ def _round(date):
         elif date.microsecond < 500000:
             return date - timedelta(microseconds=date.microsecond)
         else:
-            return date + timedelta(seconds=1) - timedelta(microseconds=date.microsecond)
+            return (
+                date + timedelta(seconds=1) - timedelta(microseconds=date.microsecond)
+            )
 
     dates = _num2date_original(
         self, time_value, only_use_cftime_datetimes, only_use_python_datetimes