Unfortunately, there is no method of evolving it at this point, until the level cap is raised, then you can level it up again after that. However, I have no time estimation for that to happen.
Also, if you happened to level it up via the switch method, I'd advise you not to do that. Sometimes when pokemon reach their evolution level when switched, it tends to not trigger the evolution. Therefore, when the level cap is raised again, I'd suggest to level it up without switching, then it should trigger the evolution when you reach the next level.