Force min cython for scikit-learn 0.24 compatibility

Author: lajohn4747

.github/workflows/minimum.yml

@@ -21,7 +21,6 @@ jobs:
     - name: Install dependencies
       run: |
           python -m pip install --upgrade pip
-          python -m pip install Cython==0.29.24
-          python -m pip install invoke .[test] --no-build-isolation
+          python -m pip install invoke .[test]
     - name: Test with minimum versions
       run: invoke minimum

pyproject.toml

@@ -40,7 +40,7 @@ dependencies = [
 "Chat" = "https://bit.ly/sdv-slack-invite"
 
 [build-system]
-requires = ['setuptools', 'wheel']
+requires = ['setuptools', 'wheel', 'cython ~= 0.29.0']
 build-backend = "setuptools.build_meta"
 
 [project.optional-dependencies]