[ruby/irb] Bump version to 1.7.1

(https://github.com/ruby/irb/pull/621)

https://github.com/ruby/irb/commit/b9a9dd97df

lib/irb/version.rb

@@ -5,7 +5,7 @@
 #
 
 module IRB # :nodoc:
-  VERSION = "1.7.0"
+  VERSION = "1.7.1"
   @RELEASE_VERSION = VERSION
-  @LAST_UPDATE_DATE = "2023-06-03"
+  @LAST_UPDATE_DATE = "2023-07-01"
 end