Revert "Prepare: run E2E smoketests with GitHub actions (#23301)" (#23553)

This reverts commit 68be3a6bcd.

server/build/gitlab-dc.mysql.yml

@@ -1,7 +1,7 @@
 version: '2.4'
 services:
   mysql:
-    image: public.ecr.aws/mattermostqa/mysql:5.7.12
+    image: ${CI_REGISTRY}/mattermost/ci/images/mysql:5.7-1
     restart: always
     environment:
       MYSQL_ROOT_HOST: "%"
@@ -83,7 +83,7 @@ services:
           - grafana
 
   start_dependencies:
-    image: mattermost/mattermost-wait-for-dep:latest
+    image: ${CI_REGISTRY}/mattermost/ci/images/mattermost-wait-for-dep:latest-1
     depends_on:
       - mysql
       - minio
@@ -95,3 +95,8 @@ services:
     command: mysql:3306 minio:9000 inbucket:9001 openldap:389 elasticsearch:9200 prometheus:9090 grafana:3000
     networks:
       default:
+
+networks:
+  default:
+    external:
+      name: ${COMPOSE_PROJECT_NAME}