ruff's isort doesn't support the no_sections option that isort upstream has. This option puts all import sinto the same import bucket.

For example, consider this source file:

import os

import bar
import blah

isort --no-sections x.py format it as

import bar
import blah
import os

As far as I can tell, there is no set of options for ruff's isort that provides this behaviour (if there is and I've missed it, I'll volunteer to add a note to the docs)