Update pg to 14 for JH pipelines

What does this MR do and why?

Failed pipeline: https://jihulab.com/gitlab-cn/gitlab/-/pipelines/1276459

Changes from: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/119344

Upgrade PG from 13 to 14.

Screenshots or screen recordings

No UI changes.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.