Update dockerfile for ruby 3.3.6 (#129)

Should have been part of #128

Author: jbakerdev

Dockerfile

@@ -5,7 +5,7 @@
 # docker run -d -p 80:80 -p 443:443 --name my-app -e RAILS_MASTER_KEY=<value from config/master.key> my-app
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version
-ARG RUBY_VERSION=3.3.5
+ARG RUBY_VERSION=3.3.6
 FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
 
 # Rails app lives here