Bump rexml from 3.3.5 to 3.3.6 (#153)

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
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -38,7 +38,7 @@ GEM
       rake (~> 13.0)
     public_suffix (6.0.1)
     rake (13.2.1)
-    rexml (3.3.5)
+    rexml (3.3.6)
       strscan
     rspec (3.13.0)
       rspec-core (~> 3.13.0)