fix: fix the homotopy logic

Author: CompRhys

botorch/optim/optimize_homotopy.py

@@ -157,7 +157,6 @@ def optimize_acqf_homotopy(
     """
     shared_optimize_acqf_kwargs = {
         "num_restarts": num_restarts,
-        "raw_samples": raw_samples,
         "inequality_constraints": inequality_constraints,
         "equality_constraints": equality_constraints,
         "nonlinear_inequality_constraints": nonlinear_inequality_constraints,
@@ -181,11 +180,14 @@ def optimize_acqf_homotopy(
         homotopy.restart()
 
         while not homotopy.should_stop:
+            # After the first iteration we don't want to generate new raw samples
+            requested_raw_samples = raw_samples if candidates is None else None
             candidates, acq_values = optimize_acqf(
                 acq_function=acq_function,
                 bounds=bounds,
                 q=1,
                 options=options,
+                raw_samples=requested_raw_samples,
                 batch_initial_conditions=candidates,
                 **shared_optimize_acqf_kwargs,
             )
@@ -204,6 +206,7 @@ def optimize_acqf_homotopy(
             bounds=bounds,
             q=1,
             options=final_options,
+            raw_samples=None,
             batch_initial_conditions=candidates,
             **shared_optimize_acqf_kwargs,
         )