Fix default value serializing

[NeevCohen]

Change Summary

Fixing a bug where default values of model fields won't be serialized into the json schema

Related issue number

Fix #8942

Checklist

• The pull request title is a good summary of the changes - it will be used in the changelog
• Unit tests for the changes exist
• Tests pass on CI
• Documentation reflects the changes where applicable
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

Selected Reviewer: @alexmojaki

[codspeed-hq]

CodSpeed Performance Report

Merging #9066 will not alter performance

_{Comparing NeevCohen:fix/ipv4-address-parsing (88feca8) with main (a3b7214)}

Summary

✅ 10 untouched benchmarks

[NeevCohen]

Please review

[sydney-runkle]

Something about this feels a bit fishy to me, but I suppose it's a pretty internal detail, so if we want to change this moving forward, we can.

Going to go ahead and merge given that @davidhewitt approved. Thanks for your review DH, and thanks @NeevCohen for the great work on this!

[sydney-runkle]

Something about this feels a bit fishy to me, but I suppose it's a pretty internal detail, so if we want to change this moving forward, we can.

I guess we're only doing this for the json schema generation, so it is relatively low stakes.

[sydney-runkle]

@NeevCohen,

Great work you've been doing! Ping me if you need any direction or advice for other issues / feature requests, if you're interested!

[NeevCohen]

@sydney-runkle
Thanks! I'd love to contribute more! I'll keep looking for new issues and see where I can help!

[davidhewitt]

I guess we're only doing this for the json schema generation, so it is relatively low stakes.

For what it's worth that was what I was thinking too. It's probably not exactly right, but it's likely better than what to_jsonable_python was doing alone. I think a more comprehensive wiring up might be a lot of work both here and in core, which wasn't clearly worth the effort.