Maintenance: Activate the new Node.js 12 for CI.

.gitlab-ci.yml

@@ -59,6 +59,7 @@ cache:
 # Initialize application env
 before_script:
   - source /etc/profile.d/rvm.sh
+  - source /opt/rh/rh-nodejs12/enable
   - bundle install -j $(nproc) --path vendor
   - bundle exec ruby .gitlab/configure_environment.rb
   - source .gitlab/environment.env

.gitlab/ci/pre.yml

@@ -6,6 +6,7 @@
     - .rules_singletest
   before_script:
     - source /etc/profile.d/rvm.sh # ensure RVM is loaded
+    - source /opt/rh/rh-nodejs12/enable # ensure Node.js is available
 
 rubocop:
   <<: *template_pre