Colocated infrastructure with MPMD application

[mellis13]

Description

In SmartSim, MPMD applications cannot be colocated with an Orchestrator. An error will be thrown if the RunSettings associated with the application has been converted to an MPMD application (

SmartSim/smartsim/entity/model.py

Line 343 in fbcc46a

if hasattr(self.run_settings, "mpmd") and len(self.run_settings.mpmd) > 0:

). However, users with MPMD applications should be able to launch the colocated Orchestrator.

Justification

This issue was reported by a user constructing online inference workflows with an MPMD application.