WordPress – Remove background image in editor

I noticed that this is a common problem, I use a dark theme and a dark background image, when I go to ADMIN> NEW POST the editor page loads the dark background image and uses all fonts and also dark colors of WordPress, It sucks and you can not see anything.
I did not find any option to configure this and by the looks it does not have yesterday configure. To solve the problem, I edited the WP_ADMIN / POST.PHP and POST_NEW.PHP files including this style sheet code (CSS) at the end of the files:

  .edit-post-layout__content,
  .edit-post-visual-editor.editor-styles-wrapper {
    background-image: none;
    background-color: #ffffff;
  }