Can't set reasoning effort minimal for gpt-5

What version of Codex is running?

0.21.0

Which model were you using?

gpt-5

What platform is your computer?

ubuntu 23

What steps can reproduce the bug?

edit gedit \~/.codex/config.toml, set the model to gpt-5 and reasoning effort to minimal. restart the terminal, open codex and send a message

What is the expected behavior?

the expected behavior was for it to work normally, but it throws an error when opening, saying that minimal is not a valid configuration

What do you see instead?

i see an error saying that minimal is not a valid configuration for reasoning effort

Additional information

_No response_