Bump rexml from 3.3.6 to 3.3.9 in /redpanda

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-version: 3.3.9
  dependency-type: indirect
...

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

Author: dependabot[bot]

redpanda/Gemfile.lock

@@ -3,6 +3,7 @@ PATH
   specs:
     testcontainers-core (0.2.0)
       docker-api (~> 2.2)
+      java-properties (~> 0.3.0)
 
 PATH
   remote: .
@@ -19,6 +20,7 @@ GEM
       multi_json
     excon (0.99.0)
     ffi (1.15.5)
+    java-properties (0.3.0)
     json (2.6.3)
     language_server-protocol (3.17.0.3)
     lint_roller (1.0.0)
@@ -37,8 +39,7 @@ GEM
       mini_portile2 (~> 2.6)
       rake (> 12)
     regexp_parser (2.8.0)
-    rexml (3.3.6)
-      strscan
+    rexml (3.3.9)
     rubocop (1.50.2)
       json (~> 2.3)
       parallel (~> 1.10)
@@ -66,7 +67,6 @@ GEM
     standard-performance (1.0.1)
       lint_roller (~> 1.0)
       rubocop-performance (~> 1.16.0)
-    strscan (3.1.0)
     unicode-display_width (2.4.2)
 
 PLATFORMS