Revert "Use the same continue-on-error (#460)"

This reverts commit 81bb0f6.

Author: eregon

.github/workflows/test.yml

@@ -37,7 +37,6 @@ jobs:
 
       - name: Run tests
         run: bundle exec rake test
-        continue-on-error: ${{ matrix.ruby == 'truffleruby' }}
 
   benchmark-default:
     runs-on: ubuntu-latest