ruby 2.4 support: upgrade ruby_parser to 3.9

Gemfile

@@ -258,7 +258,7 @@ gem 'sentry-raven', '~> 2.4.0'
 gem 'premailer-rails', '~> 1.9.0'
 
 # I18n
-gem 'ruby_parser', '~> 3.8.4', require: false
+gem 'ruby_parser', '~> 3.8', require: false
 gem 'gettext_i18n_rails', '~> 1.8.0'
 gem 'gettext_i18n_rails_js', '~> 1.2.0'
 gem 'gettext', '~> 3.2.2', require: false, group: :development

Gemfile.lock

@@ -703,7 +703,7 @@ GEM
     ruby-progressbar (1.8.1)
     ruby-saml (1.4.1)
       nokogiri (>= 1.5.10)
-    ruby_parser (3.8.4)
+    ruby_parser (3.9.0)
       sexp_processor (~> 4.1)
     rubyntlm (0.5.2)
     rubypants (0.2.0)
@@ -736,7 +736,7 @@ GEM
     sentry-raven (2.4.0)
       faraday (>= 0.7.6, < 1.0)
     settingslogic (2.0.9)
-    sexp_processor (4.8.0)
+    sexp_processor (4.9.0)
     sham_rack (1.3.6)
       rack
     shoulda-matchers (2.8.0)
@@ -1027,7 +1027,7 @@ DEPENDENCIES
   rubocop-rspec (~> 1.15.0)
   ruby-fogbugz (~> 0.2.1)
   ruby-prof (~> 0.16.2)
-  ruby_parser (~> 3.8.4)
+  ruby_parser (~> 3.8)
   rufus-scheduler (~> 3.4)
   rugged (~> 0.25.1.1)
   sanitize (~> 2.0)