As of [this commit][1] (v0.16.0), the module path of Elvish changed from
`github.com/elves/elvish` to `src.elv.sh`. This is also reflected in the
updated [packaging instructions][2].
This commit updates the `ldflags` in the derivation to use the new
module path so that `buildinfo.Reproducible` is correctly set to `true`.
[1]: 196eea21d4
[2]: https://github.com/elves/elvish/blob/master/PACKAGING.md