[master] Generic implicit mixed parameter cannot be overriden by explicit mixed in the descendant about psalm HOT 1 OPEN

<?php

/** 
 * @template TK
 * @template TV
 */
abstract class Base1 {
    /**
     * @param TK $key
     * @param TV $value
     */
    public function f($key, $value): void {}
}

/** @extends Base1<int,int> */
class Descendant1 extends Base1 {
    public function f(mixed $key, mixed $value): void {
      /** @psalm-trace $key, $value */;
    }
}

// the only difference below is the explicit mixed type for Base2::f() params

/** 
 * @template TK
 * @template TV
 */
abstract class Base2 {
    /**
     * @param TK $key
     * @param TV $value
     */
    public function f(mixed $key, mixed $value): void {}
}

/** @extends Base2<int,int> */
class Descendant2 extends Base2 {
    public function f(mixed $key, mixed $value): void {
      /** @psalm-trace $key, $value */;
    }
}