CI: trying to add tsort just once

Author: olleolleolle

.github/workflows/reline.yml

@@ -112,15 +112,15 @@ jobs:
       - name: Run irb test
         working-directory: ./irb
         run: |
-          bundle install && bundle add tsort
+          bundle install
           bundle exec rake test
       - name: Run irb yamatanooroti test
         working-directory: ./irb
         env:
           WITH_VTERM: 1
         run: |
           gem rdoc --all --ri --no-rdoc
-          bundle install && bundle add tsort
+          bundle install
           bundle exec rake test_yamatanooroti
 
   vterm-yamatanooroti: