build(deps): bump marshmallow from 3.7.1 to 3.8.0 (#207)

Bumps [marshmallow](https://github.com/marshmallow-code/marshmallow) from 3.7.1 to 3.8.0.
- [Release notes](https://github.com/marshmallow-code/marshmallow/releases)
- [Changelog](https://github.com/marshmallow-code/marshmallow/blob/dev/CHANGELOG.rst)
- [Commits](marshmallow-code/marshmallow@3.7.1...3.8.0)

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Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>