Checking Jenkins build status from only one pipeline and avoid from other pipeline pointing to same gitlab repo in PR build
As far as I can tell from reading the source code, the build status notifications are basically hard-coded into the GitLab Branch Source plugin and cannot be disabled.  Therefore, without writing your own plugin or something like that, the only way I can think of to disable the build status notifications would be to use a different method of checking out the repository that does not use the GitLab plugin, e.g. using the checkout step with a direct url.