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

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

src/marshmallow/fields.py

@@ -1497,7 +1497,9 @@ def __init__(
         precision = precision.lower()
 
         if precision not in self._unit_to_microseconds_mapping:
-            units = ", ".join(f'"{each}"' for each in self._unit_to_microseconds_mapping)
+            units = ", ".join(
+                f'"{each}"' for each in self._unit_to_microseconds_mapping
+            )
             msg = f"The precision must be one of {units}."
             raise ValueError(msg)