Make sure we error out on lazy authenticators

They return null in supports() and get called when the token storage is
accessed.

This complicates the proxy implementation, so just error out for now.

src/Auth/ProxyAuthenticator.php

@@ -32,7 +32,11 @@ class ProxyAuthenticator extends AbstractAuthenticator
     private function getAuthenticator(Request $request): ?AuthenticatorInterface
     {
         foreach ($this->authenticators as $auth) {
-            if ($auth->supports($request)) {
+            $supports = $auth->supports($request);
+            if ($supports === null) {
+                throw new \RuntimeException('Lazy authenticators not supported atm');
+            }
+            if ($supports === true) {
                 return $auth;
             }
         }