Bump phpoffice/phpspreadsheet in the composer group across 1 directory

Bumps the composer group with 1 update in the / directory: [phpoffice/phpspreadsheet](https://github.com/PHPOffice/PhpSpreadsheet).


Updates `phpoffice/phpspreadsheet` from 1.29.0 to 1.29.4
- [Release notes](https://github.com/PHPOffice/PhpSpreadsheet/releases)
- [Changelog](https://github.com/PHPOffice/PhpSpreadsheet/blob/1.29.4/CHANGELOG.md)
- [Commits](PHPOffice/PhpSpreadsheet@1.29.0...1.29.4)

---
updated-dependencies:
- dependency-name: phpoffice/phpspreadsheet
  dependency-type: indirect
  dependency-group: composer
...

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