Address review comments

Author: rahulgurnani

pkg/epp/requestcontrol/dag.go

@@ -55,6 +55,7 @@ func buildDAG(plugins []PrepareDataPlugin) map[string][]string {
 
 // prepareDataGraph builds the dependency graph and returns the plugins ordered in topological order.
 // If there is a cycle, it returns an error.
+// NOTE: The DAG is presently used for testing. In future, we may use it for executing the plugins in parallel.
 func prepareDataGraph(plugins []PrepareDataPlugin) (map[string][]string, []PrepareDataPlugin, error) {
 	dag := buildDAG(plugins)
 	nameToPlugin := map[string]PrepareDataPlugin{}