Bump rexml (#1073)

Bumps the bundler group with 1 update in the /_gems/jekyll-assets directory: [rexml](https://github.com/ruby/rexml).


Updates `rexml` from 3.3.9 to 3.4.0
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.3.9...v3.4.0)

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

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

Author: dependabot[bot]

_gems/jekyll-assets/Gemfile.lock

@@ -170,7 +170,7 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     regexp_parser (2.6.2)
-    rexml (3.3.9)
+    rexml (3.4.0)
     rouge (3.30.0)
     rspec (3.12.0)
       rspec-core (~> 3.12.0)