Omit blocked admins from repository check e-mails

Blocked admins should not receive notifications about failed repository
checks.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/63019

app/mailers/repository_check_mailer.rb

@@ -15,7 +15,7 @@ class RepositoryCheckMailer < BaseMailer
       end
 
     mail(
-      to: User.admins.pluck(:email),
+      to: User.admins.active.pluck(:email),
       subject: "GitLab Admin | #{@message}"
     )
   end

changelogs/unreleased/sh-omit-blocked-admins-from-notification.yml

+---
+title: Omit blocked admins from repository check e-mails
+merge_request: 29507
+author:
+type: fixed

spec/mailers/repository_check_mailer_spec.rb

@@ -12,6 +12,16 @@ describe RepositoryCheckMailer do
       expect(mail).to deliver_to admins.map(&:email)
     end
 
+    it 'omits blocked admins' do
+      blocked = create(:admin, :blocked)
+      admins = create_list(:admin, 3)
+
+      mail = described_class.notify(1)
+
+      expect(mail.to).not_to include(blocked.email)
+      expect(mail).to deliver_to admins.map(&:email)
+    end
+
     it 'mentions the number of failed checks' do
       mail = described_class.notify(3)