build(deps): bump rexml in /auth0_flutter/example/ios

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.6 to 3.2.8.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.6...v3.2.8)

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

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

auth0_flutter/example/ios/Gemfile.lock

@@ -24,13 +24,15 @@ GEM
     nokogiri (1.15.4-x86_64-darwin)
       racc (~> 1.4)
     racc (1.7.1)
-    rexml (3.2.6)
+    rexml (3.2.8)
+      strscan (>= 3.0.9)
     slather (2.7.4)
       CFPropertyList (>= 2.2, < 4)
       activesupport
       clamp (~> 1.3)
       nokogiri (>= 1.13.9)
       xcodeproj (~> 1.21)
+    strscan (3.1.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     xcodeproj (1.22.0)