Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -16,6 +16,8 @@
 # This specific template is located at:
 # https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Getting-Started.gitlab-ci.yml
 
+image: debian:latest
+
 stages:          # List of stages for jobs, and their order of execution
   - build
   - test
@@ -23,7 +25,6 @@ stages:          # List of stages for jobs, and their order of execution
 
 build-job:
        # This job runs in the build stage, which runs first.
-  runs-on: ubuntu-latest
   stage: build
   script:
     - echo "Compiling the code..."