CVE-2025-53942: Authentik has insufficient check for account active status when authenticating with OAuth/SAML Sources

Deactivated users that had either enrolled via OAuth/SAML or had their account connected to an OAuth/SAML account can still partially access authentik even if their account is deactivated. They end up in a half-authenticated state where they cannot access the API but crucially they can authorize applications if they know the URL of the application.