feature(core): remove unused MANTLE_PIXEL_TOKEN check in GitLab CI

gitlab-ci.yml

@@ -71,7 +71,6 @@ build web frontend:
   stage: build
   before_script:
     - if [ "$APP_ENV" == "" ]; then echo "APP_ENV is empty" ; exit 1; fi
-    - if [ "$MANTLE_PIXEL_TOKEN" == "" ]; then echo "MANTLE_PIXEL_TOKEN is empty" ; exit 1; fi
     - echo $APP_ENV;
     - node -v
     - cd web/frontend