Bump openapi-spec-validator from 0.8.2 to 0.8.4

Bumps [openapi-spec-validator](https://github.com/python-openapi/openapi-spec-validator) from 0.8.2 to 0.8.4.
- [Release notes](https://github.com/python-openapi/openapi-spec-validator/releases)
- [Commits](python-openapi/openapi-spec-validator@0.8.2...0.8.4)

---
updated-dependencies:
- dependency-name: openapi-spec-validator
  dependency-version: 0.8.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]