Add support for non-string enums in Gemini

[zaidhaan]

Closes #1553.

Gemini requires that enums must consist of only string members (e.g. currently IntEnum will cause a failure.). This PR modifies the _GeminiJsonSchema to reflect this, whilst still making it such that the output_type remains the correct type (e.g. IntEnum).

For an example, please reference the linked issue.

[zaidhaan]

I might need a bit of assistance with setting up tests. Not too familiar with pytest and how it's used in this codebase. Or if someone is willing, there's an example in the linked issue that can be used as a test case.

[DouweM]

@zaidhaan Thanks, the implementation looks good. Did you see the tests in tests/models/test_gemini.py? There are a few like test_json_def_date and test_json_def_replaced that you should be able to copy and modify to test the basic schema and then the Gemini-modified one. If you add a test to this PR, even if it's not working right yet, I can have a look at fixing it up.

[tboser]

hey @DouweM - I've also had this issue so went ahead and added a test for these changes here #1653 to get this over the line.

[zaidhaan]

Hey, sorry for the late reply..! been a bit of a busy week for me.

Thanks for offering assistance @DouweM, I didn't notice that tests liketest_json_def_replaced had pretty much what I'd needed. I can see that your implementation @tboser pretty much does exactly that.

Not sure how we want to proceed though, seems tboser's PR had their runs cancelled for some reason.

EDIT: In the mean time, I'll cherry-pick your commit onto this branch and keep an eye on CI

[zaidhaan]

I'm not sure why tests on 3.12 and 3.13 are failing. Seems to be occurring in other PRs too

[tboser]

Hey, sorry for the late reply..! been a bit of a busy week for me.

Thanks for offering assistance @DouweM, I didn't notice that tests liketest_json_def_replaced had pretty much what I'd needed. I can see that your implementation @tboser pretty much does exactly that.

Not sure how we want to proceed though, seems tboser's PR had their runs cancelled for some reason.

EDIT: In the mean time, I'll cherry-pick your commit onto this branch and keep an eye on CI

sweet no worries, didn't want to steal your work but excited to get this fix in!