Deprecate setArgument[s]? (#3383)

Author: fulldecent

Slim/Interfaces/RouteInterface.php

@@ -89,13 +89,17 @@ public function getArguments(): array;
 
     /**
      * Set a route argument
+     *
+     * @deprecated 4.14.1 Use a middleware for custom route arguments now.
      */
     public function setArgument(string $name, string $value): RouteInterface;
 
     /**
      * Replace route arguments
      *
      * @param array<string, string> $arguments
+     *
+     * @deprecated 4.14.1 Use a middleware for custom route arguments now.
      */
     public function setArguments(array $arguments): self;