Update .gitlab-ci.yml file

.gitlab-ci.yml

+# This file is a template, and might need editing before it works on your project.
+# To contribute improvements to CI/CD templates, please follow the Development guide at:
+# https://docs.gitlab.com/ee/development/cicd/templates.html
+# This specific template is located at:
+# https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Flutter.gitlab-ci.yml
+
+code_quality:
+  stage: test
+  image: "cirrusci/flutter:1.22.5"
+  before_script:
+    - pub global activate dart_code_metrics
+    - export PATH="$PATH:$HOME/.pub-cache/bin"
+  script:
+    - metrics lib -r codeclimate  > gl-code-quality-report.json
+  artifacts:
+    reports:
+      codequality: gl-code-quality-report.json
+
+