Bump rexml from 3.2.7 to 3.3.3 (#83)

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.7 to 3.3.3.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.7...v3.3.3)

---
updated-dependencies:
- dependency-name: rexml
  dependency-type: direct:development
...

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

Gemfile.lock

@@ -154,8 +154,8 @@ GEM
       abbrev
     reline (0.4.2)
       io-console (~> 0.5)
-    rexml (3.2.7)
-      strscan (>= 3.0.9)
+    rexml (3.3.3)
+      strscan
     rmagick (5.3.0)
       pkg-config (~> 1.4)
     rouge (4.0.1)