fix style checks on Python 3.12

[jameslamb]

After merging rapidsai/ci-imgs#188, style checks here started breaking like this:

python/cuvs/cuvs/test/test_doctests.py:103:24: E231 missing whitespace after ':'
python/cuvs/cuvs/test/test_doctests.py:124:27: E231 missing whitespace after ':'

(build link)

Looks like both of those are false positives (we really do intend to not have a space after the : on those lines). This proposes ignoring them with #noqa comments.

[jameslamb]

check-style is passing here: https://github.com/rapidsai/cuvs/actions/runs/10907091447/job/30269909264?pr=328

I'll ask for an admin merge.

[jameslamb]

For those finding this from search.... the better fix was just to upgrade flake8 to 7.1.1. A bug in earlier versions led to these false positives.

That was done here: #327