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

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

Author: pre-commit-ci[bot]

linopy/model.py

@@ -843,7 +843,9 @@ def add_objective(
             objective = Objective(expression=expr, model=self, sense=sense)
         else:
             sense = sense or "min"
-            objective = Objective(expression=self.linexpr(*expr), model=self, sense=sense)
+            objective = Objective(
+                expression=self.linexpr(*expr), model=self, sense=sense
+            )
 
         if not allow_constant and objective.expression.has_constant:
             raise ConstantObjectiveError(