Temporary directory is not created locally or in CI for SaaS

[AlexSkrypnyk]

SaaS project use govcms-scaffold project with settings for private and temp directory locations
vendor/govcms/scaffold-tooling/drupal/settings/all.settings.php

Private directory is set as sites/default/files/private/tmp, but locally or in CI is not created as a part of the build.

As a result of this, none of the CI tests that are relying on a real site having images coming from production using stage_file_proxy, are passing, since stage_file_proxy relies on correctly configured and existing temporary directory.

PaaS Dockerfile.cli has these lines that fix the issue

RUN fix-permissions /app/web/sites/default/files \
  && mkdir -p /app/web/sites/default/files/private/backups \
  && mkdir -p /app/web/sites/default/files/private/tmp \
  && fix-permissions /app/web/sites/default/files/private/tmp

[brett-sargeant]

This would be useful.