No, it’s not possible unfortunately. The best you can do is use where T : struct, IComparable, IConvertible, IFormattable (which of course is not the same). The interface restrictions are derived from the implementation of System.Enum.
Apart from that, you can check if typeof(T).IsEnum, which can detect the problem at runtime and presumably throw an exception. But there is no way to enforce this restriction at compile time.