[ruby/timeout] Removed deprecated names that had been warned for 5 years

https://github.com/ruby/timeout/commit/f9a9758a41

lib/timeout.rb

@@ -120,15 +120,3 @@ module Timeout
 
   module_function :timeout
 end
-
-def timeout(*args, &block)
-  warn "Object##{__method__} is deprecated, use Timeout.timeout instead.", uplevel: 1
-  Timeout.timeout(*args, &block)
-end
-
-# Another name for Timeout::Error, defined for backwards compatibility with
-# earlier versions of timeout.rb.
-TimeoutError = Timeout::Error
-class Object
-  deprecate_constant :TimeoutError
-end