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

This reverts commit 68be3a6bcd.

server/build/gitlab-dc.schemapostgres.yml

@@ -1,7 +1,7 @@
 version: '2.4'
 services:
   postgres:
-    image: public.ecr.aws/mattermostqa/postgres:12
+    image: ${CI_REGISTRY}/mattermost/ci/images/postgres:10-1
     restart: always
     environment:
       POSTGRES_USER: mmuser
@@ -21,9 +21,14 @@ services:
           - postgres
 
   start_dependencies:
-    image: mattermost/mattermost-wait-for-dep:latest
+    image: ${CI_REGISTRY}/mattermost/ci/images/mattermost-wait-for-dep:latest-1
     depends_on:
       - postgres
     command: postgres:5432
     networks:
       default:
+
+networks:
+  default:
+    external:
+      name: ${COMPOSE_PROJECT_NAME}