Update import paths for base multi-objective acquisition functions (#…

…2708)

Summary:
Pull Request resolved: #2708

As titled. Follow up to D61721280.

Reviewed By: esantorella

Differential Revision: D61733064

fbshipit-source-id: d3c68d5ce0e6af376e5490712ac8dea9d03a1112

ax/models/torch/utils.py

@@ -26,10 +26,8 @@
     qSimpleRegret,
     SampleReducingMCAcquisitionFunction,
 )
-from botorch.acquisition.multi_objective.analytic import (
+from botorch.acquisition.multi_objective.base import (
     MultiObjectiveAnalyticAcquisitionFunction,
-)
-from botorch.acquisition.multi_objective.monte_carlo import (
     MultiObjectiveMCAcquisitionFunction,
 )
 from botorch.acquisition.multi_objective.multi_output_risk_measures import (