Update /tmp/images/ci_files/variables.yml for 12.8.2

ci_files/variables.yml

 ---
 variables:
   GITLAB_ELASTICSEARCH_INDEXER_VERSION: v2.1.0
-  GITLAB_VERSION: v12.8.1
-  GITLAB_REF_SLUG: v12.8.1
-  GITLAB_ASSETS_TAG: v12.8.1
+  GITLAB_VERSION: v12.8.2
+  GITLAB_REF_SLUG: v12.8.2
+  GITLAB_ASSETS_TAG: v12.8.2
   GITLAB_EXPORTER_VERSION: 6.1.0
   GITLAB_SHELL_VERSION: v11.0.0
   GITLAB_WORKHORSE_VERSION: v8.21.0
   GITLAB_CONTAINER_REGISTRY_VERSION: v2.8.1-gitlab
-  GITALY_SERVER_VERSION: v12.8.1
+  GITALY_SERVER_VERSION: v12.8.2
   GIT_VERSION: 2.24.1
   GO_VERSION: 1.12.13
   KUBECTL_VERSION: 1.13.12