Bump snakeyaml from 1.29 to 1.31

Resolves CVE-2022-25857, among other fixes.

Author: chadlwilson

lib/psych/versions.rb

@@ -5,6 +5,6 @@ module Psych
   VERSION = '3.3.2'
 
   if RUBY_ENGINE == 'jruby'
-    DEFAULT_SNAKEYAML_VERSION = '1.29'.freeze
+    DEFAULT_SNAKEYAML_VERSION = '1.31'.freeze
   end
 end