Bump rexml from 3.3.3 to 3.3.9

Bumps [rexml](https://github.com/ruby/rexml) from 3.3.3 to 3.3.9.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.3.3...v3.3.9)

---
updated-dependencies:
- dependency-name: rexml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -12,7 +12,7 @@ gem 'mini_racer'
 gem 'bootsnap', '~> 1.4.2'
 
 # rexml gem is a bundled gem since Ruby 3.0.0.
-gem 'rexml', '~> 3.3.3'
+gem 'rexml', '~> 3.3.9'
 
 gem 'normalize-rails'
 gem 'interactor'

Gemfile.lock

@@ -347,8 +347,7 @@ GEM
     responders (3.1.0)
       actionpack (>= 5.2)
       railties (>= 5.2)
-    rexml (3.3.3)
-      strscan
+    rexml (3.3.9)
     rspec (3.12.0)
       rspec-core (~> 3.12.0)
       rspec-expectations (~> 3.12.0)
@@ -406,7 +405,6 @@ GEM
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     stackprof (0.2.24)
-    strscan (3.1.0)
     thor (1.3.1)
     tilt (2.1.0)
     timeout (0.3.2)
@@ -483,7 +481,7 @@ DEPENDENCIES
   rails (= 6.1.7.6)
   rails-controller-testing
   record_tag_helper (~> 1.0)
-  rexml (~> 3.3.3)
+  rexml (~> 3.3.9)
   rspec-rails
   rubocop (~> 0.62.0)
   sassc-rails