new_contents: from readthedocs.builds.version_slug import VERSION_SLUG_REGEX
  from readthedocs.projects.constants import LANGUAGES_REGEX, PROJECT_SLUG_REGEX
  
  
  pattern_opts = {
      'project_slug': PROJECT_SLUG_REGEX,
      'lang_slug': LANGUAGES_REGEX,
      'version_slug': VERSION_SLUG_REGEX,
      'filename_slug': '(?:.*)',
  }
  
subject: Break out patterns into a top-level constants file