Bump symfony/process from 6.1.3 to 6.4.26 in /tools/php-cs-fixer

Bumps [symfony/process](https://github.com/symfony/process) from 6.1.3 to 6.4.26.
- [Release notes](https://github.com/symfony/process/releases)
- [Changelog](https://github.com/symfony/process/blob/7.3/CHANGELOG.md)
- [Commits](symfony/process@v6.1.3...v6.4.26)

---
updated-dependencies:
- dependency-name: symfony/process
  dependency-version: 6.4.26
  dependency-type: indirect
...

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

Author: dependabot[bot]