Fix typo in serialization.mdx

[eltociear]

What does this PR do?

overriden -> overridden

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

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[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint.

[LysandreJik]

Hey @eltociear! The code quality error comes from a new release from black. Rebasing on main should solve the issue as you'll benefit from #17918.

Let us know if we can help!

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

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