Deprecations for PHP 8.1 get_class() and get_called_class() without argument

[nkazarynava]

In scope of PHP8.1 compatibility static analysis it was discovered some deprecations in webflo/drupal-finder codebase:

1. line 56 vendor/webflo/drupal-finder/tests/DrupalFinderTestBase.php get_called_class() without argument (tag 1.2.2)
   Proposed change: replacing get_called_class() with static::class

[nkazarynava]

Pull request has been created Deprecations for PHP 8.1