Get incorrect user when merge code or add a comment

### What feature do you want to see added?

When someone triggers a merge action or adds a comment for a merge request, Jenkins gets the wrong user & user email.
In fact, someone who commits the code and someone who adds a comment or triggers a merge request is not the same.

Below's code in NoteHookTriggerHandlerImpl.java and MergeRequestHookTriggerHandlerImpl.java should be replaced.
`
.withUserName(hook.getMergeRequest().getLastCommit().getAuthor().getName())
.withUserEmail(hook.getMergeRequest().getLastCommit().getAuthor().getEmail())
`

Below's is new fix code
`
.withUserName(hook.getUser().getUsername())
.withUserEmail(hook.getUser().getUserEmail())
`

### Upstream changes

_No response_