The reviewer in MR does not change
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### Summary
If you change the person in Reviewer field in the MR, it will remain the same. The new reviewer will not be applied.
### Steps to reproduce
1. Create new MR;
2. Open this MR;
3. On the right in the Reviewer field we assign a person "Jack", for example. Click in the inactive zone to apply the changes;
4. In the Reviewer field we now have a "Jack" selected (Screenshot 1);
5. Now we click "Edit" in Reviewer field. Select the reviewer to "Carl". When choosing, it turns out that the checkboxes are set "Jack" and "Carl";
6. In the Reviewer field we now have a "Carl" selected (Screenshot 2);
7. Click "Edit" in Reviewer field. Select the reviewer to "Jack" without deleting the old reviewer.
7. The reviewer will not change (it should be "Jack" but "Carl" is standing there) (Screenshot 2).
### Example Project
<!-- If possible, please create an example project here on GitLab.com that exhibits the problematic
behavior, and link to it here in the bug report. If you are using an older version of GitLab, this
will also determine whether the bug is fixed in a more recent version. -->
### What is the current *bug* behavior?
The reviewer is not changing correctly.
### What is the expected *correct* behavior?
The reviewer must be updated to a new one when changing.
### Relevant logs and/or screenshots
### Output of checks
<!-- If you are reporting a bug on GitLab.com, uncomment below -->
<!-- This bug happens on GitLab.com -->
<!-- and uncomment below if you have /label privileges -->
<!-- /label ~"reproduced on GitLab.com" -->
<!-- or follow up with an issue comment of `@gitlab-bot label ~"reproduced on GitLab.com"` if you do not -->
#### Results of GitLab environment info
```
System information
System: Ubuntu 24.04
Proxy: no
Current User: git
Using RVM: no
Ruby Version: 3.2.5
Gem Version: 3.5.23
Bundler Version:2.5.11
Rake Version: 13.0.6
Redis Version: 7.0.15
Sidekiq Version:7.2.4
Go Version: unknown
GitLab information
Version: 17.7.1-ee
Revision: 3c8f631cd0a
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: PostgreSQL
DB Version: 14.11
URL: https://gitlab...
HTTP Clone URL: https://gitlab...
SSH Clone URL: git@gitlab...:some-group/some-project.git
Elasticsearch: no
Geo: no
Using LDAP: no
Using Omniauth: yes
Omniauth Providers:
GitLab Shell
Version: 14.39.0
Repository storages:
- default: unix:/var/opt/gitlab/gitaly/gitaly.socket
GitLab Shell path: /opt/gitlab/embedded/service/gitlab-shell
Gitaly
- default Address: unix:/var/opt/gitlab/gitaly/gitaly.socket
- default Version: 17.7.1
- default Git Version: 2.47.0
```
#### Results of GitLab application Check
```
Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 14.39.0 ? ... OK (14.39.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/gitlab-shell-check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes (cluster/worker) ... 1/1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Database config exists? ... yes
Tables are truncated? ... skipped
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Cable config exists? ... yes
Resque config exists? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Systemd unit files or init script exist? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Systemd unit files or init script up-to-date? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Projects have namespace: ...
1/2 ... yes
...
864/834 ... yes
Redis version >= 6.2.14? ... yes
Ruby version >= 3.0.6 ? ... yes (3.2.5)
Git user has default SSH configuration? ... yes
Active users: ... 159
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes
Elasticsearch version 7.x-8.x or OpenSearch version 1.x ... skipped (Advanced Search is disabled)
All migrations must be finished before doing a major upgrade ... skipped (Advanced Search is disabled)
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished
```
</pre>
</details>
### Possible fixes
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issue