Bump tinymce/tinymce from 7.7.2 to 7.8.0 (#4766)

Bumps [tinymce/tinymce](https://github.com/tinymce/tinymce-dist) from 7.7.2 to 7.8.0.
- [Changelog](https://github.com/tinymce/tinymce-dist/blob/master/CHANGELOG.md)
- [Commits](tinymce/tinymce-dist@7.7.2...7.8.0)

---
updated-dependencies:
- dependency-name: tinymce/tinymce
  dependency-version: 7.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]