Describe the bug
When I create a SAML provider with a real certificate (e.g. Let's Encrypt) for signing then the metadata is not created or updated. Trying to download the metadata fails in consequence.
The bug does not happen when there is no certificate or a generated certificate selected for signing.

To Reproduce
Steps to reproduce the behavior:

1. Create a SAML provider
2. As signing certificate select a real certificate (e.g. Let's Encrypt) imported via the certs-docker-mountpoint
3. Click Finish
4. View SAML Provider Metadata
5. See missing Metadata

Expected behavior
Metadata should be created/updated no matter of the signing certificate

Version and Deployment (please complete the following information):

• authentik version: 2025.6.3
• Deployment: docker-compose