[ruby/forwardable] Bump version to 1.3.0

https://github.com/ruby/forwardable/commit/e56f0f83c6

lib/forwardable/version.rb

@@ -1,5 +1,5 @@
 module Forwardable
   # Version of +forwardable.rb+
-  VERSION = "1.2.0"
+  VERSION = "1.3.0"
   FORWARDABLE_VERSION = VERSION
 end