Do not use sudo in CI.

.gitlab-ci.yml

 test:
   image: python:3.8-buster
   before_script:
-    - sudo apt-get update -qq
-    - sudo apt-get install -qq yarnpkg
+    - apt-get update -y -qq && apt-get install -y -qq yarnpkg
     - pip install -q Django
     - pip install .
     - pip install -r requirements_dev.txt