Bump phpunit/phpunit from 9.6.19 to 11.5.1 in /graph-tutorial

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.6.19 to 11.5.1.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/11.5.1/ChangeLog-11.5.md)
- [Commits](sebastianbergmann/phpunit@9.6.19...11.5.1)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

graph-tutorial/composer.json

@@ -19,7 +19,7 @@
         "laravel/sail": "^1.0.1",
         "mockery/mockery": "^1.4.4",
         "nunomaduro/collision": "^6.1",
-        "phpunit/phpunit": "^9.5.10",
+        "phpunit/phpunit": "^11.5.1",
         "spatie/laravel-ignition": "^1.0"
     },
     "autoload": {