o4-mini was repeated multiple times and prevented applying custom configs

[00sapo]

Currently, custom configs are applied to the first model having a specific name found in MODEL_SETTINGS.

However, it's not obvious that it's the same model that will be picked up for chatting.

I noticed this for o4-mini, but it may happen for other models also.

Another solution could be transforming the list into a dict.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}