Fix errcheck issue for saml.go file (#28546)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

server/.golangci.yml

@@ -90,7 +90,6 @@ issues:
         channels/api4/reaction_test.go|\
         channels/api4/remote_cluster.go|\
         channels/api4/role_test.go|\
-        channels/api4/saml.go|\
         channels/api4/scheme.go|\
         channels/api4/scheme_test.go|\
         channels/api4/shared_channel.go|\