Fix "Dynamic call to static method"

I wonder if we should change this. Drupal 10 uses $this->assertEquals() all over the place.

Perhaps that it is required in a future version of PHP/Drupal? Is there a Drupal core issue that suggests to change this?

Hmm, I made this change in all my own code since I trust PHPStorm :), but upon looking into it more, there is no consensus about this in core: #3029358: Change tests calling static methods as '$this->' to 'static::' →

Also, Commerce punted the decision to core and decided to leave it in place: #3029321: Change tests calling static methods as '$this->' to 'static::' →

So, I'll go ahead and close this now until the core policy changes.

ptmkenny → closed merge request !32