bug: unable to run iex command under macOS Big Sur

Hi Everyone,
I've tried installing a large number of Elixir versions of my system, but none of them works from asdf.
Command like `iex` or `asdf exec iex` return
```
exit status 1
```
The binaries themselves are functional, as a call to
```
.asdf/installs/elixir/1.19.4-otp-27/bin/iex
```
launches a working prompt.

I'm using asdf 1.18.0 on macOS Big Sur
`asdf info` returns:
```
OS:
Darwin Fs-MacBook-Pro.local 20.6.0 Darwin Kernel Version 20.6.0: Thu Jul 6 22:12:47 PDT 2023; root:xnu-7195.141.49.702.12~1/RELEASE_X86_64 x86_64

SHELL:
zsh 5.8 (x86_64-apple-darwin20.0)

BASH VERSION:
3.2.57(1)-release

ASDF VERSION:
0.18.0 (revision unknown)

ASDF INTERNAL VARIABLES:
ASDF_TOOL_VERSIONS_FILENAME=.tool-versions
ASDF_DATA_DIR=/Users/daniel/.asdf
ASDF_CONFIG_FILE=/Users/daniel/.asdfrc

ASDF INSTALLED PLUGINS:
elixir https://github.com/asdf-vm/asdf-elixir.git
f4ca7d50973d777240c04d7278c916d93d2a7efe
erlang https://github.com/asdf-vm/asdf-erlang.git
6744df773596ec681792ca112ff0c495af63de75
```
Other plugins, including erlang work correctly.
I've tried reinstalling my plugins and asdf several time, but this didn't help with the problem.
Thank you in advance for your help!

Start by reproducing `asdf exec iex` and `iex` on macOS Big Sur, then compare them with the directly invoked `.asdf/installs/elixir/1.19.4-otp-27/bin/iex`. Use the reported asdf and plugin versions to trace executable resolution. Done means the asdf-managed commands launch the working IEx prompt.

Written by the indexing model from the issue text.