Ruby

Fix memory leak of Ractor basket when sending to closed Ractor

The following script leaks memory:

r = Ractor.new { }
r.value

10.times do
  100_000.times do
    r.send(123)
  rescue Ractor::ClosedError
  end

  puts `ps -o rss= -p #{$$}`
end

Before:

18508
25420
32460
40012
47308
54092
61132
68300
75724
83020

After:

11432
11432
11432
11432
11432
11432
11432
11432
11432
11688