Bump symfony/security-http from 7.1.5 to 7.1.8 in /lib/php/core-bundle

Bumps [symfony/security-http](https://github.com/symfony/security-http) from 7.1.5 to 7.1.8.
- [Release notes](https://github.com/symfony/security-http/releases)
- [Changelog](https://github.com/symfony/security-http/blob/7.1/CHANGELOG.md)
- [Commits](symfony/security-http@v7.1.5...v7.1.8)

---
updated-dependencies:
- dependency-name: symfony/security-http
  dependency-type: indirect
...

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