Bump rexml from 3.2.5 to 3.3.9

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.5 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@v3.2.5...v3.3.9)

---
updated-dependencies:
- dependency-name: rexml
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -79,7 +79,7 @@ GEM
     regexp_parser (2.6.1)
     reline (0.3.3)
       io-console (~> 0.5)
-    rexml (3.2.5)
+    rexml (3.3.9)
     rubocop (1.42.0)
       json (~> 2.3)
       parallel (~> 1.10)