power_assert.rb:8: warning: tracing (e.g. set_trace_func) will not capture all events without --debug flag

`jruby 9.4.1.0 (3.1.0) 2023-02-07 237d5fa5f4 OpenJDK 64-Bit Server VM 11.0.18+10 on 11.0.18+10 +jit [x86_64-linux]`
See https://github.com/ruby/timeout/actions/runs/4187122427/jobs/7256547037
Due to this, JRuby fails *all* `assert_separately` tests.