Fix action_dispatch deprecation warning

This change addresses the following deprecation warnings:
```
DEPRECATION WARNING: Setting action_dispatch.show_exceptions to false is deprecated. Set to :none instead. (called from rescue in call at /usr/share/rvm/gems/ruby-3.0.5@upstream/gems/actionpack-7.1.3.4/lib/action_dispatch/middleware/debug_exceptions.rb:43)
DEPRECATION WARNING: Setting action_dispatch.show_exceptions to false is deprecated. Set to :none instead. (called from rescue in call at /usr/share/rvm/gems/ruby-3.0.5@upstream/gems/actionpack-7.1.3.4/lib/action_dispatch/middleware/show_exceptions.rb:36)
```

config/environments/test.rb

@@ -31,7 +31,7 @@
   config.action_controller.perform_caching = false
 
   # Raise exceptions instead of rendering exception templates.
-  config.action_dispatch.show_exceptions = false
+  config.action_dispatch.show_exceptions = :none
 
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false