[CI] Use node version 16 for all CI jobs

.gitlab-ci.yml

@@ -25,7 +25,7 @@ stages:
 review_front:
   interruptible: true
   stage: review
-  image: node:12-buster
+  image: node:16-buster
   when: manual
   allow_failure: true
   variables:
@@ -129,7 +129,7 @@ flake8:
 
 eslint:
   interruptible: true
-  image: node:12-buster
+  image: node:16-buster
   stage: lint
   allow_failure: true
   before_script:
@@ -212,7 +212,7 @@ test_front:
 
 build_front:
   stage: build
-  image: node:12-buster
+  image: node:16-buster
   before_script:
     - curl -L -o /usr/local/bin/jq https://github.com/stedolan/jq/releases/download/jq-1.5/jq-linux64
     - chmod +x /usr/local/bin/jq