[ruby/irb] Bump version to 1.8.3

(https://github.com/ruby/irb/pull/731)

https://github.com/ruby/irb/commit/de79375ac1

lib/irb/version.rb

@@ -5,7 +5,7 @@
 #
 
 module IRB # :nodoc:
-  VERSION = "1.8.2"
+  VERSION = "1.8.3"
   @RELEASE_VERSION = VERSION
-  @LAST_UPDATE_DATE = "2023-10-12"
+  @LAST_UPDATE_DATE = "2023-10-14"
 end