try to test JRuby

Author: hsbt

.github/workflows/test.yml

@@ -10,7 +10,6 @@ jobs:
   ruby-versions:
     uses: ruby/actions/.github/workflows/ruby_versions.yml@master
     with:
-      engine: cruby-truffleruby
       min_version: 2.6
 
   irb:
@@ -50,6 +49,8 @@ jobs:
           - ruby: 2.6
           - ruby: truffleruby
           - ruby: truffleruby-head
+          - ruby: jruby
+          - ruby: jruby-head
       fail-fast: false
     env:
       WITH_LATEST_RELINE: ${{matrix.with_latest_reline}}