Bump mpdf/mpdf from 8.2.3 to 8.2.4

Bumps [mpdf/mpdf](https://github.com/mpdf/mpdf) from 8.2.3 to 8.2.4.
- [Release notes](https://github.com/mpdf/mpdf/releases)
- [Changelog](https://github.com/mpdf/mpdf/blob/development/CHANGELOG.md)
- [Commits](mpdf/mpdf@v8.2.3...v8.2.4)

---
updated-dependencies:
- dependency-name: mpdf/mpdf
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]