chore(deps): bump decap-cms from 3.0.12 to 3.1.8 (#424)

Bumps [decap-cms](https://github.com/decaporg/decap-cms) from 3.0.12 to 3.1.8.
- [Release notes](https://github.com/decaporg/decap-cms/releases)
- [Changelog](https://github.com/decaporg/decap-cms/blob/main/CHANGELOG.md)
- [Commits](https://github.com/decaporg/decap-cms/compare/decap-cms@3.0.12...decap-cms@3.1.8)

---
updated-dependencies:
- dependency-name: decap-cms
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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