Use rubocop --format github instead of problem matcher (#38519)

.github/workflows/lint-ruby.yml

@@ -42,11 +42,8 @@ jobs:
         with:
           bundler-cache: true
 
-      - name: Set-up RuboCop Problem Matcher
-        uses: r7kamura/rubocop-problem-matchers-action@59f1a0759f50cc2649849fd850b8487594bb5a81 # v1.2.2
-
       - name: Run rubocop
-        run: bin/rubocop
+        run: bin/rubocop --format github
 
       - name: Run brakeman
         if: always() # Run both checks, even if the first failed