Bump auth0/auth0-php from 5.7.0 to 8.3.1

Bumps [auth0/auth0-php](https://github.com/auth0/auth0-PHP) from 5.7.0 to 8.3.1.
- [Release notes](https://github.com/auth0/auth0-PHP/releases)
- [Changelog](https://github.com/auth0/auth0-PHP/blob/8.3.1/CHANGELOG.md)
- [Upgrade guide](https://github.com/auth0/auth0-PHP/blob/main/UPGRADE.md)
- [Commits](auth0/auth0-PHP@5.7.0...8.3.1)

---
updated-dependencies:
- dependency-name: auth0/auth0-php
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

composer.json

@@ -20,7 +20,7 @@
         "monolog/monolog": "^1.11",
         "slim/psr7": "^1.4",
         "symfony/yaml": "^4.3",
-        "auth0/auth0-php": "^5.7",
+        "auth0/auth0-php": "^8.3",
         "beberlei/assert": "^3.2",
         "cultuurnet/culturefeed-php": "^1.10",
         "cultuurnet/udb3-api-guard": "^v4.0.0",