elixir: make mix interpreter path absolute

Remove the implicit dependency on `elixir` being somewhere in `PATH`.

Before:

```
$ nix build '.#elixir_1_15'
$ ./result/bin/mix --version
env: ‘elixir’: No such file or directory
```

After:

```
$ nix build '.#elixir_1_15'
$ ./result/bin/mix --version
Erlang/OTP 25 [erts-13.2.2.2] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1] [jit]

Mix 1.15.2 (compiled with Erlang/OTP 25)
```

This was caused by the shebang interpreter directive being set to
`${coreutils}/bin/env elixir`, whereas now the `elixir` part is replaced
with the full path to the interpreter.

We can't get rid of the `${coreutils}/bin/env` part, because without it
all scripts are interpreted as shell scripts.

0 files changed, 0 insertions, 0 deletions