Add o4 model prefix to MODEL_PREFIX_TO_ENCODING and MODEL_TO_ENCODING

[ColemanDunn]

Adds for the o4- to the MODEL_PREFIX_TO_ENCODING dictionary and o4 to MODEL_TO_ENCODING. 4.1 has been added in another PR

[taylorn-ai]

Seems like no one is actually reviewing these PRs... Anyway, I would suggest that you add a test for the o4 models, perhaps similar to what I have done in #407

[hauntsaninja]

Thanks, this is fixed in recent versions of tiktoken

[kuzminT]

Thanks, this is fixed in recent versions of tiktoken

Thanks for fixing this in recent versions of tiktoken. However, I'm thinking about the approach taken here. There were community PRs addressing these issues that sat without response for months, only to be closed after you implemented your own solution.
While I understand maintainers may prefer their own implementation, completely ignoring community contributions without explanation doesn't align well with open source principles. Contributors invested time and effort into these PRs, and they deserved at least acknowledgment or feedback about why the approach wasn't suitable.
Perhaps it would be helpful to add some guidance in the README about your contribution process - whether you're actively reviewing community PRs or prefer to handle development internally.

[taylorn-ai]

Couldn’t have said it better myself.