Clean up comments in cancel-on-close paths

- Remove unnecessary partial-generation comment from GenerateActivityCancelCommandsForClose.
- Simplify comment in TerminateWorkflow, add matching comment in TimeoutWorkflow.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: rkannan82

service/history/workflow/mutable_state_impl.go

@@ -4615,8 +4615,6 @@ func (ms *MutableStateImpl) GenerateActivityCancelCommandsForClose() error {
 		)
 	}
 
-	// Best-effort: if one queue fails, earlier queues may already have tasks generated.
-	// This is acceptable because the workflow is being closed regardless.
 	for controlQueue, commands := range commandsByQueue {
 		if err := ms.AddWorkerCommandsTasks(commands, controlQueue); err != nil {
 			return err

service/history/workflow/util.go

@@ -99,6 +99,7 @@ func TimeoutWorkflow(
 		return err
 	}
 
+	// Proactively cancel in-flight activities so they don't run uselessly after the workflow is closed.
 	return mutableState.GenerateActivityCancelCommandsForClose()
 }
 
@@ -150,8 +151,7 @@ func TerminateWorkflow(
 		return err
 	}
 
-	// Proactively cancel in-flight activities by dispatching worker commands to workers
-	// that support control queues, so they don't run uselessly after the workflow is closed.
+	// Proactively cancel in-flight activities so they don't run uselessly after the workflow is closed.
 	return mutableState.GenerateActivityCancelCommandsForClose()
 }