mongos_manual_intervention_actions.js was originally introduced because it used to be the case that when shard collection would encounter inconsistent metadata for the collection it would throw ManualInterventionRequired, in this case the hooks in mongos_manual_intervention_actions.js would be trigger they would retry the command after clearing the inconsistent collection metadata.

In 5.0 we introduced a new ShardCollection implementation that handles these inconsistencies internally and will never surface a ManualInterventionRequired to the client.

Since the legacy ShardCollection implementation has been removed in (5.1) SERVER-58652. We can now safely remove also mongos_manual_intervention_actions.js