✨ Validate SAML Metadata URL

<Card href="https://humansignal.com/goenterprise"> <img style="pointer-events: none; margin-left: 0px; margin-right: 0px;" src="https://docs.humansignal.com/images/badge.svg" alt="Label Studio Enterprise badge"/> <p style="margin-top: 10px; font-size: 14px;"> This endpoint is not available in Label Studio Community Edition. [Learn more about Label Studio Enterprise](https://humansignal.com/goenterprise) </p> </Card> Validate a SAML metadata URL by fetching it and checking for valid XML, without saving.