fix the 'skipping run' on 'existing exec output for output_modules': …

…only use it if there are no stores to write. race condition with other jobs could lead to that condition

service/tier2.go

@@ -691,11 +691,6 @@ func GetExecutionPlan(
 			}
 			existingExecOuts[name] = file
 
-			if runningLastStage && name == outputModule {
-				logger.Info("found existing exec output for output_module, skipping run", zap.String("output_module", name))
-				return nil, nil
-			}
-
 		case pbsubstreams.ModuleKindStore:
 			file, readErr := c.ReadFile(ctx, &block.Range{StartBlock: moduleStartBlock, ExclusiveEndBlock: stopBlock})
 			if readErr != nil {
@@ -725,6 +720,11 @@ func GetExecutionPlan(
 
 	}
 
+	if runningLastStage && len(storesToWrite) == 0 && existingExecOuts[outputModule] != nil {
+		logger.Info("found existing exec output for output_module and no stores to produce, skipping run", zap.String("output_module", outputModule))
+		return nil, nil
+	}
+
 	for name, module := range requiredModules {
 		if _, exists := existingExecOuts[name]; exists {
 			continue // for stores that need to be run for the partials, but already have cached execution outputs