[8.x] Update PHPDoc of Collection::forget() (#40283)

* Update PHPDoc of Collection::forget()

* Update src/Illuminate/Collections/Collection.php

Co-authored-by: Dries Vints <[email protected]>

Co-authored-by: Taylor Otwell <[email protected]>
Co-authored-by: Dries Vints <[email protected]>

Author: 3 people

src/Illuminate/Collections/Collection.php

@@ -397,7 +397,7 @@ public function flip()
     /**
      * Remove an item from the collection by key.
      *
-     * @param  string|array  $keys
+     * @param  string|int|array  $keys
      * @return $this
      */
     public function forget($keys)
@@ -1628,7 +1628,7 @@ public function offsetSet($key, $value)
     /**
      * Unset the item at a given offset.
      *
-     * @param  string  $key
+     * @param  mixed  $key
      * @return void
      */
     #[\ReturnTypeWillChange]