Fix Dockerfile ruby version

[kemagain]

Dockerfile references an outdated version of ruby, update to 3.3.4 to match the gemfile.

there are still other things that you have to do for cold-start development that aren't addressed in this pr since they have some level of actual thinking i'd have to do:

• changing the Dockerfile rails env to development
• Dockerfile fixes for WSL (must use named volumes)
• docker-compose: must set postgres credentials or trust mode

[pupgray]

OHHH thanks! Yeah, can you tell I don't use the docker image much? haha