sources/saml: fix pickle error, add saml auth tests (#10348) * test with persistent nameid * fix pickle * user_write: dont attempt to write to read only property * add test for enroll + auth * unwrap lazy user --------- Signed-off-by: Jens Langhammer <jens@goauthentik.io> Co-authored-by: Jens L <jens@goauthentik.io>