emacs: fix `env` shallow merge

Fixes regression caused by #252244.

`env` was first defined in its own attrset, which was merged with a
second attrset:

```nix
...
{
   env = {
     NATIVE_FULL_AOT = "1";
     LIBRARY_PATH = lib.concatStringsSep ":" libGccJitLibraryPaths;
   };
} // {
...
   env.NIX_CFLAGS_COMPILE = ...
...
}
```

In this situation, the `env` from the first attrset is not preserved,
since `//` does a shallow merge.

Signed-off-by: Andrew Pan <a@tny.town>

0 files changed, 0 insertions, 0 deletions