Migrate dependencies to /data/olympia

[KevinMind]

Relates: mozilla/addons#15066

Description

• Updated docker-compose.yml to mount dependencies in /data/olympia/deps for better organization.
• Modified Dockerfile to set environment variables for dependency directories and ensure proper ownership.
• Adjusted Makefile-docker to remove NODE_MODULES variable and streamline npm commands.
• Updated documentation to reflect changes in dependency paths.
• Refactored install_deps.py to clean up dependency directories and removed obsolete package.json copying logic.
• Updated settings_base.py to reference new dependency paths.

Context

Effectively, we are moving the path to pip and node dependencies to where you would find them on the host (/data/olympia) ./deps and ./node_modules.

This gives us a few benefits:

• centralizes all code for our image to one parent folder instead of splitting dependencies out to /deps. simpler file permissions management
• enables mounting a single docker volume to mount the ./deps into the correct location instead of having to remap that within the container to /deps
• enables running npm commands without having to define custom paths to node modules and executables. npm run "command" just works now.

Testing

Run "make down && make up" to run with fresh volumes.

You should notice that changes in ./deps or ./node_modules on the host are propogated into the container.

Checklist

• Add #ISSUENUM at the top of your PR to an existing open issue in the mozilla/addons repository.
• Successfully verified the change locally.
• The change is covered by automated tests, or otherwise indicated why doing so is unnecessary/impossible.
• Add before and after screenshots (Only for changes that impact the UI).
• Add or update relevant docs reflecting the changes made.