composer(deps): update symfony/clock requirement in /packages/guides

Updates the requirements on [symfony/clock](https://github.com/symfony/clock) to permit the latest version.
- [Release notes](https://github.com/symfony/clock/releases)
- [Changelog](https://github.com/symfony/clock/blob/7.0/CHANGELOG.md)
- [Commits](symfony/clock@v6.4.2...v6.4.3)

---
updated-dependencies:
- dependency-name: symfony/clock
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/guides/composer.json

@@ -28,7 +28,7 @@
         "league/uri": "^6.5 || ^7.0",
         "phpdocumentor/flyfinder": "^1.1",
         "psr/event-dispatcher": "^1.0",
-        "symfony/clock": "^6.4.2",
+        "symfony/clock": "^6.4.3",
         "symfony/string": "^5.4 || ^6.3 || ^7.0",
         "symfony/translation-contracts": "^3.4.1",
         "symfony/http-client": "^6.4.2",