Enable e2e testing with docker-compose on GitLab (#17765)

* Make testing with docker-compose work on GitLab.

* Comment heavy jobs.

* Make testing with docker-compose work on GitLab.

* Comment heavy jobs.

* Fix images

* Addressing review.

build/dotenv/test-schema-validation.env

@@ -1,10 +1 @@
-CI_INBUCKET_HOST=inbucket
-CI_MINIO_HOST=minio
-CI_INBUCKET_PORT=10080
-CI_MINIO_PORT=9000
-CI_INBUCKET_SMTP_PORT=10025
-CI_LDAP_HOST=openldap
 IS_CI=true
-MM_EMAILSETTINGS_SMTPSERVER=inbucket
-MM_EMAILSETTINGS_SMTPPORT=10025
-MM_ELASTICSEARCHSETTINGS_CONNECTIONURL=http://elasticsearch:9200