feat(router): remove deprecated preheat API endpoints (#4574)

Signed-off-by: Gaius <gaius.qi@gmail.com>

Author: gaius-qi

manager/router/router.go

@@ -255,13 +255,6 @@ func Init(cfg *config.Config, logDir string, service service.Service, database *
 	oc.GET(":id", h.GetCluster)
 	oc.GET("", h.GetClusters)
 
-	// TODO Remove this api.
-	// Compatible with the V1 preheat.
-	pv1 := r.Group("/preheats")
-	r.GET("_ping", h.GetHealth)
-	pv1.POST("", h.CreateV1Preheat)
-	pv1.GET(":id", h.GetV1Preheat)
-
 	// Health Check.
 	r.GET("/healthy", h.GetHealth)