Ruby lsp in devcontainer config

[plural]

This PR does a few things, all for development and testing:

• Removes VS Code extensions we don't need from the devcontainer
• Sets up the Ruby LSP to handle formatting on save (including rubocop)
• Fixes an issue with the Ruby LSP seeing factory bot loading factories twice, causing errors and hangs in the LSP
• Adds launch configs for a debugging-enabled version of the server and a config to attach to it, enabling live debugging of a running server.
• Adds a debugging launch config for rake tasks, prompting for the name of a task to run and debug.