test_function.rb: try running test_nogvl_poll again

According to some runs in mjit-test (make test-all RUN_OPTS="--jit-wait"),
this test might not be the cause of its failure.

So, let me try running this again.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64426 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/fiddle/test_function.rb

@@ -73,10 +73,6 @@ module Fiddle
     end
 
     def test_nogvl_poll
-      if RubyVM::MJIT.enabled?
-        skip 'r64355 make `make test-all RUN_OPTS="--jit-wait"` hang and CI running it times out.'
-      end
-
       # XXX hack to quiet down CI errors on EINTR from r64353
       # [ruby-core:88360] [Misc #14937]
       # Making pipes (and sockets) non-blocking by default would allow