[ruby/timeout] Freeze VERSION

https://github.com/ruby/timeout/commit/ac7b010c41

lib/timeout.rb

@@ -23,7 +23,7 @@
 # Copyright:: (C) 2000  Information-technology Promotion Agency, Japan
 
 module Timeout
-  VERSION = "0.1.1"
+  VERSION = "0.1.1".freeze
 
   # Raised by Timeout.timeout when the block times out.
   class Error < RuntimeError