Bump container registry to v3.18.1

What does this MR do?

3.18.1 (2021-12-10)

Bug Fixes

• revert enable PostgreSQL pageinspect extension (2c2825c)

Related issues

Related to gitlab-org/container-registry#532 (closed). This MR reverts a problematic schema migration that prevented the deployment of v3.18.0 (see gitlab-com/gl-infra/k8s-workloads/gitlab-com!1397 (comment 761053524)). There is no need to do something about self-managed, this is only applicable to GitLab.com for now.

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated