Remove old monolog 1.x compat code (#42392)

Author: GrahamCampbell

src/Illuminate/Log/LogManager.php

@@ -420,7 +420,7 @@ protected function prepareHandler(HandlerInterface $handler, array $config = [])
             $handler = new FingersCrossedHandler($handler, $this->actionLevel($config));
         }
 
-        if (Monolog::API !== 1 && (Monolog::API !== 2 || ! $handler instanceof FormattableHandlerInterface)) {
+        if (! $handler instanceof FormattableHandlerInterface) {
             return $handler;
         }