Bump rexml in /common/jenkins-agents/terraform-2408/docker

Bumps [rexml](https://github.com/ruby/rexml) from 3.3.5 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@v3.3.5...v3.3.6)

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

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

common/jenkins-agents/terraform-2408/docker/Gemfile.lock

@@ -1838,7 +1838,7 @@ GEM
       trailblazer-option (>= 0.1.1, < 0.2.0)
       uber (< 0.2.0)
     retriable (3.1.2)
-    rexml (3.3.5)
+    rexml (3.3.6)
       strscan
     rspec (3.12.0)
       rspec-core (~> 3.12.0)