ci: Pin user_saml to stable-7

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

Author: kesselb

.github/workflows/files-external-smb-kerberos.yml

@@ -57,6 +57,7 @@ jobs:
           persist-credentials: false
           repository: nextcloud/user_saml
           path: apps/user_saml
+          ref: 'stable-7'
 
       - name: Install user_saml
         run: |