Bump marshmallow from 3.26.1 to 4.0.1 in /flowmachine

Bumps [marshmallow](https://github.com/marshmallow-code/marshmallow) from 3.26.1 to 4.0.1.
- [Changelog](https://github.com/marshmallow-code/marshmallow/blob/dev/CHANGELOG.rst)
- [Commits](marshmallow-code/marshmallow@3.26.1...4.0.1)

---
updated-dependencies:
- dependency-name: marshmallow
  dependency-version: 4.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Author: dependabot[bot]