`isort: skip` not working when futures imports are present

[sondrelg]

Bug summary

isort: skip seems to not work when there is a futures imports are present.

Reproducible example

Running isort test.py on this example works well. No changes are made.

# test.py
from foo import bar  # isort: skip
from bar import baz

baz + bar

When modifying the file to include a futures import:

from __future__ import annotations

from foo import bar  # isort: skip
from bar import baz

baz + bar

isort now moves the marked import to the bottom.