shellHook: make it actually run

When we changed this in I91cb6eb6668f3a8eace36ecbdb01eb367861d77b to
not run in nested shells, we didn't predict that `nix develop` would do
something ridiculous and append -env to things silently. `nix-shell` of
course does not do this, so we need to tolerate both.

Change-Id: Ibe7cf546823d7358ebc0414ecbe154e3e3194f45

package.nix

@@ -449,7 +449,10 @@ stdenv.mkDerivation (finalAttrs: {
           shellHook = ''
             # don't re-run the hook in (other) nested nix-shells
             function lixShellHook() {
-              if [[ $name != lix-shell-env ]]; then
+              # n.b. how the heck does this become -env-env? well, `nix develop` does it:
+              # https://git.lix.systems/lix-project/lix/src/commit/7575db522e9008685c4009423398f6900a16bcce/src/nix/develop.cc#L240-L241
+              # this is, of course, absurd.
+              if [[ $name != lix-shell-env && $name != lix-shell-env-env ]]; then
                 return;
               fi