Base: avoid losing Method provenance in `@enum` (#61932)
Improves stacktraces and `methods(...)` queries for any Methods defined
through @enum:
```julia
julia> @enum Fruit Apple=1 Banana=2
julia> methods(Fruit)
[1] Fruit(x::Integer)
@ REPL[6]:1
```
versus before:
```julia
julia> methods(Fruit)
[1] Fruit(x::Integer)
@ Enums.jl:211
```
