Bump rexml from 3.2.6 to 3.3.9

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.6 to 3.3.9.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.6...v3.3.9)

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

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

Gemfile.lock

@@ -60,7 +60,7 @@ GEM
       observer (~> 0.1)
       string-similarity (~> 2.1)
       tty-option (~> 0.1)
-    rexml (3.2.6)
+    rexml (3.3.9)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)
@@ -142,7 +142,7 @@ CHECKSUMS
   regexp_parser (2.9.0) sha256=81a00ba141cec0d4b4bf58cb80cd9193e5180836d3fa6ef623f7886d3ba8bdd9
   reline (0.5.3) sha256=2c46747a1dfd03e100f0666d8a374cf2930c3e734298af9b39e5fe8d35b42035
   retest (1.13.2) sha256=f5abd78b72f5e85fb61f0368b78a84b89008ab9a954ee5c0978729d68cefbfb8
-  rexml (3.2.6) sha256=e0669a2d4e9f109951cb1fde723d8acd285425d81594a2ea929304af50282816
+  rexml (3.3.9) sha256=d71875b85299f341edf47d44df0212e7658cbdf35aeb69cefdb63f57af3137c9
   rspec (3.13.0) sha256=d490914ac1d5a5a64a0e1400c1d54ddd2a501324d703b8cfe83f458337bab993
   rspec-core (3.13.0) sha256=557792b4e88da883d580342b263d9652b6a10a12d5bda9ef967b01a48f15454c
   rspec-expectations (3.13.0) sha256=621d48c62262f955421eaa418130744760802cad47e781df70dba4d9f897102e