pyproject.toml: scikit-learn>=1.9.1

Removed deprecated scikit-learn version specifications and updated to version 1.9.1.

Author: cclauss

pyproject.toml

@@ -23,9 +23,7 @@ dependencies = [
   "pandas>=2.3.3",
   "pillow>=11.3",
   "rich>=13.9.4",
-  # https://github.com/scikit-learn/scikit-learn/issues/34898
-  "scikit-learn @ https://github.com/scikit-learn/scikit-learn.git ; python_version>='3.15'",
-  "scikit-learn>=1.9; python_version<'3.15'",
+  "scikit-learn>=1.9.1",
   "scipy>=1.18.1",
   "statsmodels>=0.14.4",
   "sympy>=1.13.3",