Revert "Introduce Fiber Scheduler `blocking_region` hook. (#11963)" (#12013)

This reverts some of commit 87fb44dff6409a19d12052cf0fc07ba80a4c45ac.

We will rename and propose a slightly different interface.

1 files changed, 0 insertions, 4 deletions

diff --git a/test/fiber/scheduler.rb b/test/fiber/scheduler.rb
index 91fba0476e..e6a8256232 100644
--- a/test/fiber/scheduler.rb
+++ b/test/fiber/scheduler.rb
@@ -309,10 +309,6 @@ class Scheduler
       Addrinfo.getaddrinfo(hostname, nil).map(&:ip_address).uniq
     end.value
   end
-
-  def blocking_region(work)
-    Thread.new(&work).join
-  end
 end
 
 # This scheduler class implements `io_read` and `io_write` hooks which require