Remove the dependency on github.com/modern-go/reflect2

[dominiquelefevre]

reflect2 is too brittle because of the reliance on the internals of the golang's compiler. Moreover, it is no longer maintained: github.com/modern-go/reflect2..

Replace the usages of github.com/modern-go/reflect2 with stdlib's reflect.

[fioncat]

Agreed, after i updated go to 1.20, reflect2 panic directly, this is awful.