Set DOCKER_TLS_CERTDIR in Auto Dev-Ops CI template

https://gitlab.com/gitlab-org/gitlab-ce/issues/65019

changelogs/unreleased/65019-auto-devops-dind-tls-fix.yml

+---
+title: Set DOCKER_TLS_CERTDIR in Auto Dev-Ops CI template to fix jobs using Docker-in-Docker
+merge_request: 31078
+author:
+type: fixed

lib/gitlab/ci/templates/Auto-DevOps.gitlab-ci.yml

@@ -57,6 +57,8 @@ variables:
 
   ROLLOUT_RESOURCE_TYPE: deployment
 
+  DOCKER_TLS_CERTDIR: "" # https://gitlab.com/gitlab-org/gitlab-runner/issues/4501
+
 stages:
   - build
   - test