Bump rexml from 3.3.3 to 3.3.6

Bumps [rexml](https://github.com/ruby/rexml) from 3.3.3 to 3.3.6.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.3.3...v3.3.6)

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

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

Gemfile.lock

@@ -197,7 +197,7 @@ GEM
     regexp_parser (2.8.3)
     reline (0.4.1)
       io-console (~> 0.5)
-    rexml (3.3.3)
+    rexml (3.3.6)
       strscan
     rubocop (1.59.0)
       json (~> 2.3)