[TMP] Test both head and release for now

Author: eregon

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.0', 3.1, truffleruby]
+        ruby: ['3.0', 3.1, truffleruby, truffleruby-head]
 
     env:
       JAVA_OPTS: '-Xmx1024m'