Switch to truffleruby-head for now, we will likely need kwargs fixes anyway

Author: eregon

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7, '3.0', 3.1, jruby, truffleruby]
+        ruby: [2.4, 2.5, 2.6, 2.7, '3.0', 3.1, jruby, truffleruby-head]
 
     env:
       JAVA_OPTS: '-Xmx1024m'