If Build running change accept merge request when build succeeds button from orange to blue

## What does this MR do?

If Build running change accept merge request when build succeeds button from orange to blue

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

I didn't really check, but to my knowledge these changes should fix it. Would love to know how to set up working pipelines in my local build.

## Why was this MR needed?

orange was to big a warning color for this button


## Screenshots (if relevant)

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/c9100be272c5567ee4dfa281cffaeb7a/_24266_merge-request-01.png)
![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/bb84ea5b519fc67babf8383f3b396fb7/_24266_merge-request-02.png)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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?


Closes #24266

See merge request !7577