Bump rexml from 3.2.6 to 3.3.6

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.6 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@v3.2.6...v3.3.6)

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

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -251,7 +251,8 @@ GEM
     resque-pause (0.3.0)
       multi_json (~> 1.0)
       resque (>= 1.9.10)
-    rexml (3.2.6)
+    rexml (3.3.6)
+      strscan
     rubocop (1.52.1)
       json (~> 2.3)
       parallel (~> 1.10)
@@ -316,6 +317,7 @@ GEM
     stimulus-rails (1.3.3)
       railties (>= 6.0.0)
     stringio (3.1.0)
+    strscan (3.1.0)
     thor (1.3.1)
     tilt (2.3.0)
     timeout (0.4.1)