chore(contracts): update Viper OpenAPI pin

[github-actions]

Scheduled drift check detected a change in the live Viper OpenAPI spec.

Source: https://viper-xi.vercel.app/api/openapi.json

oasdiff exit code: 0 (1 = breaking changes for assets-processIntegrationCreate)

oasdiff output:

No changes detected
::notice::Non-breaking Viper OpenAPI changes:
No changes detected
No breaking Viper OpenAPI changes detected

Automated by contracts.yml drift job.

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Summary by cubic

Update the pinned Viper OpenAPI spec to the latest version and refresh uv.lock. oasdiff reports no API changes (exit code 0), so no breaking changes.

^{Written for commit f428d7b. Summary will update on new commits.}