Bump onelogin/php-saml from 4.1.0 to 4.3.1 in /services/drupal

Bumps [onelogin/php-saml](https://github.com/SAML-Toolkits/php-saml) from 4.1.0 to 4.3.1.
- [Release notes](https://github.com/SAML-Toolkits/php-saml/releases)
- [Changelog](https://github.com/SAML-Toolkits/php-saml/blob/4.3.1/CHANGELOG)
- [Commits](SAML-Toolkits/php-saml@4.1.0...4.3.1)

---
updated-dependencies:
- dependency-name: onelogin/php-saml
  dependency-version: 4.3.1
  dependency-type: indirect
...

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Author: dependabot[bot]