MNT Fix CI issue from new scikit-learn==1.8.0 (#503)

* add sklearn1.8 test runs

* run gha

* use reg_param to avoid singularity

* lint

* Delete pixi.lock

* Uncomment conditional for pytest job

* Add back pixi.lock

* bump up python version

Co-authored-by: Adrin Jalali <adrin.jalali@gmail.com>

* bump up numpy version

Co-authored-by: Adrin Jalali <adrin.jalali@gmail.com>

* comment out catboost dep

* scikit-learn nightly ver is 1.9.dev0

* update pixi lock

* comment to TODO for catboost issue

* Update build-test.yml

* undo mistake delete

---------

Co-authored-by: Adrin Jalali <adrin.jalali@gmail.com>

Author: divakaivan

.github/workflows/build-test.yml

@@ -23,6 +23,7 @@ jobs:
           ci-sklearn15,
           ci-sklearn16,
           ci-sklearn17,
+          ci-sklearn18,
           ci-sklearn-nightly
         ]