Try not upgrading/installing pip/setuptools either on Cygwin

Author: EliahKagan

.github/workflows/cygwin-test.yml

@@ -60,11 +60,6 @@ jobs:
         # This is used unless, and before, an updated pip is installed.
         ln -s pip3 /usr/bin/pip
 
-    - name: Update PyPA packages
-      run: |
-        # Get the latest pip, and prior to Python 3.12, setuptools.
-        python -m pip install -U pip $(pip freeze --all | grep -ow ^setuptools)
-
     - name: Install project and test dependencies
       run: |
         pip install ".[test]"