build(deps): bump rexml from 3.2.5 to 3.2.6

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.5 to 3.2.6.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.5...v3.2.6)

---
updated-dependencies:
- dependency-name: rexml
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -74,7 +74,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.2.5)
+    rexml (3.2.6)
     rouge (4.2.0)
     rubyzip (2.3.2)
     safe_yaml (1.0.5)