Bump Dockerfile to 3.3.4

Signed-off-by: Zach Gollwitzer <[email protected]>

Dockerfile

@@ -1,7 +1,7 @@
 # syntax = docker/dockerfile:1
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
-ARG RUBY_VERSION=3.3.1
+ARG RUBY_VERSION=3.3.4
 FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim as base
 
 # Rails app lives here