Merge branch 'feature/fix-23230' into '8-12-stable'

Fix #23230: Update mailroom to 0.8.1 in Gemfile.lock

## What does this MR do?

Update mailroom to 0.8.1 in Gemfile.lock

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?
8.12.5 introduced a bug which put 2 different versions of mail_room in Gemfile.lock, probably due to a merge error.

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
#23230 

Closes #23230

See merge request !6814

Gemfile.lock

@@ -399,7 +399,7 @@ GEM
       systemu (~> 2.6.2)
     mail (2.6.4)
       mime-types (>= 1.16, < 4)
-    mail_room (0.8.0)
+    mail_room (0.8.1)
     method_source (0.8.2)
     mime-types (2.99.3)
     mimemagic (0.3.0)