fix(active_job): avoid shared queue race in jruby

Co-Authored-By: github-copilot <noreply@example.com>

Author: solnic

sentry-rails/spec/active_job/shared_examples/tracing/worker_hub_isolation.rb

@@ -20,8 +20,8 @@ def perform
 
     Sentry.get_current_scope.set_tags(test_thread: true)
 
-    thread_a = worker_thread { job_a.perform_later; drain }
-    thread_b = worker_thread { job_b.perform_later; drain }
+    thread_a = worker_thread { job_a.perform_now }
+    thread_b = worker_thread { job_b.perform_now }
     [thread_a, thread_b].each(&:join)
 
     txn_a = transactions.find { |t| t.tags[:job] == "A" }