db: add db upgrade for 5.39 and upgrade to 6 (#18645)

model/version.go

@@ -14,6 +14,7 @@ import (
 // release at the front of the list.
 var versions = []string{
 	"6.0.0",
+	"5.39.0",
 	"5.38.0",
 	"5.37.0",
 	"5.36.0",