Bump rexml from 3.3.6 to 3.3.9

Bumps [rexml](https://github.com/ruby/rexml) from 3.3.6 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@v3.3.6...v3.3.9)

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

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

Gemfile.lock

@@ -453,8 +453,7 @@ GEM
       io-console (~> 0.5)
     request_store (1.7.0)
       rack (>= 1.4)
-    rexml (3.3.6)
-      strscan
+    rexml (3.3.9)
     rouge (4.3.0)
     rqrcode (2.2.0)
       chunky_png (~> 1.0)
@@ -567,7 +566,6 @@ GEM
     stimulus-rails (1.3.4)
       railties (>= 6.0.0)
     stringio (3.1.1)
-    strscan (3.1.0)
     tailwindcss-rails (2.7.3-aarch64-linux)
       railties (>= 7.0.0)
     tailwindcss-rails (2.7.3-arm64-darwin)