[ci] remove jruby-head until we can address #2490

Author: solnic

.github/workflows/sentry_ruby_test.yml

@@ -18,6 +18,7 @@ jobs:
     with:
       engine: cruby-jruby
       min_version: 2.4
+      versions: '["2.6", "2.7", "3.0", "3.1", "3.2", "3.3", "head", "jruby"]'
   test:
     needs: ruby-versions
     defaults: