fix: update bundler to v2.5.23 for Dependabot compatibility

Dependabot only supports bundler v2.* but Gemfile.lock specified v1.17.2.
Updated BUNDLED WITH section to use bundler 2.5.23.

Fixes Dependabot error:
"Dependabot detected the following bundler requirement for your project: '1'.
Currently, the following bundler versions are supported in Dependabot: v2.*."

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jeremyeder

docs/Gemfile.lock

@@ -278,4 +278,4 @@ DEPENDENCIES
   webrick
 
 BUNDLED WITH
-   1.17.2
+   2.5.23