Improve GitLab Pages build speed

.gitlab-ci.yml

@@ -1,15 +1,15 @@
-image: ruby:2.6
+image: jekyll/jekyll:4
 
 variables:
   JEKYLL_ENV: production
   LC_ALL: C.UTF-8
 
 before_script:
-  - gem install bundler jekyll
-  - bundle install
+  - rm Gemfile.lock
 
 test:
   stage: test
+  interruptible: true
   script:
     - bundle exec jekyll build -d test
   artifacts:
@@ -20,6 +20,9 @@ test:
 
 pages:
   stage: deploy
+  interruptible: true
+  before_script:
+    - rm Gemfile.lock
   script:
     - bundle exec jekyll build -d public
   artifacts: