Exclude trainee maintainer from `#reviewer?`

Since there is `#trainee_maintainer?`, we should get
trainee_maintainer purely using `#trainee_maintainer?` to avoid
confusion such as https://gitlab.com/gitlab-com/www-gitlab-com/-/issues/9119

lib/gitlab/danger/roulette.rb

@@ -147,6 +147,7 @@ module Gitlab
             spin_role_for_category(team, role, project, category)
           end
         hungry_reviewers = reviewers.select { |member| member.hungry }
+        hungry_traintainers = traintainers.select { |member| member.hungry }
 
         # TODO: take CODEOWNERS into account?
         # https://gitlab.com/gitlab-org/gitlab/issues/26723
@@ -156,7 +157,7 @@ module Gitlab
         # Make hungry traintainers have 4x the chance to be picked as a reviewer
         # Make traintainers have 3x the chance to be picked as a reviewer
         # Make hungry reviewers have 2x the chance to be picked as a reviewer
-        weighted_reviewers = reviewers + hungry_reviewers + traintainers + traintainers
+        weighted_reviewers = reviewers + hungry_reviewers + traintainers + traintainers + traintainers + hungry_traintainers
         reviewer = spin_for_person(weighted_reviewers, random: random, timezone_experiment: timezone_experiment)
         maintainer = spin_for_person(maintainers, random: random, timezone_experiment: timezone_experiment)
 

lib/gitlab/danger/teammate.rb

@@ -32,10 +32,8 @@ module Gitlab
         projects&.has_key?(name)
       end
 
-      # Traintainers also count as reviewers
       def reviewer?(project, category, labels)
-        has_capability?(project, category, :reviewer, labels) ||
-          traintainer?(project, category, labels)
+        has_capability?(project, category, :reviewer, labels)
       end
 
       def traintainer?(project, category, labels)