Bump symfony/process from 6.4.8 to 6.4.15

Bumps [symfony/process](https://github.com/symfony/process) from 6.4.8 to 6.4.15.
- [Release notes](https://github.com/symfony/process/releases)
- [Changelog](https://github.com/symfony/process/blob/7.1/CHANGELOG.md)
- [Commits](symfony/process@v6.4.8...v6.4.15)

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

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