Bump mpdf/mpdf from 8.1.6 to 8.2.0

Bumps [mpdf/mpdf](https://github.com/mpdf/mpdf) from 8.1.6 to 8.2.0.
- [Release notes](https://github.com/mpdf/mpdf/releases)
- [Changelog](https://github.com/mpdf/mpdf/blob/development/CHANGELOG.md)
- [Commits](mpdf/mpdf@v8.1.6...v8.2.0)

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

Signed-off-by: dependabot[bot] <[email protected]>