[8.x] Allow tap() on Paginator (#37682)

Before

```php
$posts = App\Models\Post::search('Laravel')->paginate();

$posts->load('user');

return $posts;
```

After

```php
return App\Models\Post::search('Laravel')
    ->paginate()
    ->tap(fn ($posts) => $posts->load('author'));
```

Signed-off-by: Mior Muhammad Zaki <[email protected]>

src/Illuminate/Pagination/AbstractCursorPaginator.php

@@ -10,13 +10,14 @@
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
 use Illuminate\Support\Traits\ForwardsCalls;
+use Illuminate\Support\Traits\Tappable;
 
 /**
  * @mixin \Illuminate\Support\Collection
  */
 abstract class AbstractCursorPaginator implements Htmlable
 {
-    use ForwardsCalls;
+    use ForwardsCalls, Tappable;
 
     /**
      * All of the items being paginated.

src/Illuminate/Pagination/AbstractPaginator.php

@@ -8,13 +8,14 @@
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
 use Illuminate\Support\Traits\ForwardsCalls;
+use Illuminate\Support\Traits\Tappable;
 
 /**
  * @mixin \Illuminate\Support\Collection
  */
 abstract class AbstractPaginator implements Htmlable
 {
-    use ForwardsCalls;
+    use ForwardsCalls, Tappable;
 
     /**
      * All of the items being paginated.