MM-19872: Update dependencies for enterprise implementation of new SAML2 golib. (#13298)

* Update dependencies for enterprise implementation of new SAML2 golib.

* add indirect

cmd/mattermost/main.go

@@ -18,6 +18,7 @@ import (
 	_ "github.com/gorilla/handlers"
 	_ "github.com/hako/durafmt"
 	_ "github.com/hashicorp/memberlist"
+	_ "github.com/mattermost/gosaml2"
 	_ "github.com/mattermost/ldap"
 	_ "github.com/mattermost/rsc/qr"
 	_ "github.com/prometheus/client_golang/prometheus"