fix ruff complaints

Author: adrianmolzon

bayes_opt/bayesian_optimization.py

@@ -375,9 +375,9 @@ def save_state(self, path: str | PathLike[str]) -> None:
         """
         if len(self._space) == 0:
             msg = (
-                    "Cannot save optimizer state before collecting any samples. "
-                    "Please probe or register at least one point before saving."
-                )
+                "Cannot save optimizer state before collecting any samples. "
+                "Please probe or register at least one point before saving."
+            )
             raise ValueError(msg)
 
         random_state = None

tests/test_acquisition.py

@@ -405,7 +405,7 @@ def verify_optimizers_match(optimizer1, optimizer2):
         assert optimizer1.space._constraint.ub == optimizer2.space._constraint.ub
 
     rng = np.random.default_rng()
-    assert rng.bit_generator.state['state']['state'] == rng.bit_generator.state['state']['state']
+    assert rng.bit_generator.state["state"]["state"] == rng.bit_generator.state["state"]["state"]
 
     assert optimizer1._gp.kernel.get_params() == optimizer2._gp.kernel.get_params()