CI: Pin scikit-learn<=1.1.3 due to broken scikit-optimize

Author: kernc

setup.py

@@ -46,7 +46,7 @@
             'test': [
                 'seaborn',
                 'matplotlib',
-                'scikit-learn',
+                'scikit-learn <= 1.1.3',  # Pinned due to boken scikit-optimize
                 'scikit-optimize',
             ],
             'dev': [