chores: formatting and reduce verbosity in makefile

[SethFalco]

Just some chores while I was looking at this locally.

1. We forgot to put root = true in our .editorconfig.
2. In the Makefile, it was actually using the global instance of Python. This is due to a quirk in Makefile, we need to execute the chain of commands at once from Make's perspective to actually use the venv.
3. Minor formatting change of REUSE.toml.