Prevent TypeError when using create_attribute Twig function

Problem/Motivation

Except for "standard" variables like attributes, content_attributes... it is not easy to know if a variable value is already an Attribute object or a still a mapping to convert with create_attribute().

This is an issue because it is very easy to trigger errors:

• if we put an attribute object in the constructor of create_attribute() function, a WSOD TypeError error is raised.
• if we print a mapping, we got an user error: "invalid render array key in Drupal\Core\Render\Element::children()"
• if we execute a method on a mapping, nothing is happening (silent error)

This can be avoided by ugly (and often forgotten) workarounds like this one:
{% set link_attributes = link_attributes.storage() is defined ? link_attributes : create_attribute(link_attributes) %}

So, we need to find a way of avoiding any error.

Steps to reproduce

Twig code: {{ create_attribute(create_attribute()) }}

Result: TypeError: "Drupal\Core\Template\TwigExtension::createAttribute(): Argument #1 ($attributes) must be of type array, Drupal\Core\Template\Attribute given

Proposed resolution

Something like that (non tested code draft):

/**
   * Creates an Attribute object.
   *
   * @param Attribute|array $attributes
   *   (optional) An existing attribute object. Or an associative array of key-value pairs to be converted to
   *   HTML attributes.
   *
   * @return \Drupal\Core\Template\Attribute
   *   An attributes object that has the given attributes.
   */
  public function createAttribute(Attribute|array $attributes = []) {
    if (\is_array($attributes)) {
      return new Attribute($attributes);
    }
    return $attributes;
  }

With maybe some changes to do in TwigExtensionTest.

User interface changes

No

API changes

Nothing breakable

Data model changes

No