Try with python39-pip=23.0.1-1

And don't upgrade it or other PyPI packages.

Author: EliahKagan

.github/workflows/cygwin-test.yml

@@ -30,7 +30,7 @@ jobs:
     - name: Install Cygwin
       uses: cygwin/cygwin-install-action@v4
       with:
-        packages: python39 python39-pip python39-virtualenv git wget
+        packages: python39 python39-pip=23.0.1-1 python39-virtualenv git
         add-to-path: false  # No need to change $PATH outside the Cygwin environment.
 
     - name: Arrange for verbose output
@@ -55,20 +55,9 @@ jobs:
         # and cause subsequent tests to fail
         cat test/fixtures/.gitconfig >> ~/.gitconfig
 
-    - name: Ensure the "pip" command is available
-      run: |
-        # 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, wheel, and prior to Python 3.12, setuptools.
-        wget -P ~/.cache/pip 'https://files.pythonhosted.org:443/packages/c7/c3/55076fc728723ef927521abaa1955213d094933dc36d4a2008d5101e1af5/wheel-0.42.0-py3-none-any.whl'
-        python -m pip install -U pip $(pip freeze --all | grep -ow ^setuptools) wheel
-
     - name: Install project and test dependencies
       run: |
-        pip install ".[test]"
+        python -m pip install ".[test]"
 
     - name: Show version and platform information
       run: |