[CIEXE-1312] Migrate off legacy GitLab runner (#6139)

Co-authored-by: luu.vo <luu.vo@datadoghq.com>

Author: henryvo117

.gitlab-ci.yml

@@ -264,7 +264,7 @@ check_merge_labels:
 
 generate_system_tests_lambda_proxy_image:
   image: registry.ddbuild.io/ci/libdatadog-build/ci_docker_base:67145216
-  tags: ["runner:docker"]
+  tags: ["docker-in-docker:amd64"]
   needs: []
   stage: system-tests-utils
   allow_failure: false