Addresses an error like the following:
```sh-session
$ sudo darwin-rebuild --verbose --print-build-logs switch
building the system configuration...
fetching git input 'git+file:///private/etc/nix-darwin'
error:
… while evaluating an expression to select 'drvPath' on it
at «internal»:1:552:
… while evaluating strict
at «internal»:1:552:
(stack trace truncated; use '--show-trace' to show the full trace)
error: 'vim_configurable' has been renamed to/replaced by 'vim-full'
```
See <853d9f31ea>
Fixesnix-darwin/nix-darwin#1622
89abe5ba46