Restore implicit ensurepip in venv

Author: EliahKagan

.github/workflows/cygwin-test.yml

@@ -58,13 +58,9 @@ jobs:
 
     - name: Set up virtualenv
       run: |
-        python3.9 -m venv --without-pip .venv
+        python3.9 -m venv .venv
         echo 'BASH_ENV=.venv/bin/activate' >>"$GITHUB_ENV"
 
-    - name: Bootstrap pip in virtualenv
-      run: |
-        wget -qO- https://bootstrap.pypa.io/get-pip.py | python
-
     - name: Update PyPA packages
       run: |
         # Get the latest pip, wheel, and prior to Python 3.12, setuptools.

test/test_installation.py

@@ -4,19 +4,11 @@
 import ast
 import os
 import subprocess
-import sys
-
-import pytest
 
 from test.lib import TestBase, VirtualEnvironment, with_rw_directory
 
 
 class TestInstallation(TestBase):
-    @pytest.mark.xfail(
-        sys.platform == "cygwin" and "CI" in os.environ,
-        reason="Trouble with pip on Cygwin CI, see issue #2004",
-        raises=subprocess.CalledProcessError,
-    )
     @with_rw_directory
     def test_installation(self, rw_dir):
         venv = self._set_up_venv(rw_dir)