Fix X_pending and constraints errors

Author: shuds13

optimas/generators/ax/service/multi_fidelity.py

@@ -124,7 +124,11 @@ def _create_generation_steps(
             GenerationStep(
                 model=Models.BOTORCH_MODULAR,
                 num_trials=-1,
-                model_kwargs=bo_model_kwargs,
+                model_kwargs={
+                    **bo_model_kwargs,
+                    "acquisition_options": {"X_pending": None,
+                                            "constraints": None}
+                },
                 model_gen_kwargs={
                     "model_gen_options": {
                         Keys.ACQF_KWARGS: {