maintainers/team-list: add emily to LLVM

This has been de facto the case for a while now anyway, given
its inseparability from my `stdenv` and Darwin team roles,
especially after <https://github.com/NixOS/nixpkgs/pull/354107> and
<https://github.com/NixOS/nixpkgs/pull/440273>. Might as well make
sure I don’t miss pings, although I can’t promise I’ll be able
to proactively review stuff that falls outside the scope that matters
to me.

maintainers/team-list.nix

@@ -736,6 +736,7 @@ with lib.maintainers;
   llvm = {
     members = [
       dtzWill
+      emily
       ericson2314
       lovek323
       qyliss