runtime events: disable flaky test (#3830)

The test has been observed to fail on bytecode too, disable it.

Author: gretay-js

testsuite/tests/lib-runtime-events/test_dropped_events.ml

@@ -9,9 +9,9 @@
    include unix;
    set OCAMLRUNPARAM = "e=6";
    hasunix;
+   arch_amd64;
    { bytecode; }
    {
-    arch_amd64;
     native;
    }
  }