Release 9.2.7

Cherry-pick merge requests labeled [Pick into Stable] for the current milestone (you can take advantage of the Pick into Stable 9.2 merged merge requests page) into the CE 9-2-stable and EE 9-2-stable-ee branches, respectively.
Merge CE 9-2-stable into EE 9-2-stable-ee following the [Merging a CE stable branch into its EE counterpart] guide
Sync CE, EE, and Omnibus to dev
Check for any problematic migrations in EE (EE migrations include CE ones), and paste the diff in a snippet: git v9.2.6-ee..9-2-stable-ee -- db/migrate db/post_migrate =>
Check omnibus-gitlab/9-2-stable CHANGELOG.md
Check omnibus-gitlab/9-2-stable-ee CHANGELOG.md
While waiting for tests to be green, now is a good time to start on the blog post: https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/6510
Ensure tests are green on CE stable branch
Ensure tests are green on EE stable branch
Ensure tests are green on Omnibus CE stable branch
Ensure tests are green on Omnibus EE stable branch
In #releases: I'm going to tag 9.2.7

Tag the 9.2.7 version using the release task:

```sh
# In the release-tools project:
bundle exec rake "release[9.2.7]"
```

Check that EE packages are built, CE packages are built and appears on packages.gitlab.com: EE / CE
Create the 9.2.7 version on https://version.gitlab.com
Deploy the blog post

Tweet (prepare the Tweet text below or paste the tweet URL instead):

```
GitLab 9.2.7 is released! BLOG_POST_URL DESCRIPTION OF THE CHANGES
```

In the 9.2 Regressions issue:
- Add the following notice:
```
`9.2.7` has been tagged, further fixes will go into `9.2.8` as necessary.
```
- Remove notes for the regressions fixed by version 9.2.7
Add omnibus-gitlab/9.2.7+ce.0 CHANGELOG.md items to omnibus-gitlab/master CHANGELOG.md

For references:

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