Test local env for all systems

Some of the tests are irrelevant to Windows. These were mearked to be skipped when run on Windows machine.
Added one test for Windows, wchich is skipped for a non-Windows run.

tests/test_local_env.py

@@ -1,4 +1,6 @@
 """Verify behavior of package module looking at a given Python environment."""
+import os
+import platform
 import sys
 import venv
 from pathlib import Path
@@ -46,6 +48,23 @@
     os.path.join("Lib", "site-packages"),
 ]
 
+
+@pytest.mark.skipif(
+    platform.system() != "Windows", reason="Not relevant to Windows virtual environment"
+)
+@pytest.mark.parametrize(
+    "subdir", [pytest.param(d, id=f"venv:{d}") for d in windows_subdirs]
+)
+def test_find_package_dirs__various_paths_in_venv_windows(tmp_path, subdir):
+    venv.create(tmp_path, with_pip=False)
+    path = tmp_path / subdir
+    expect = {tmp_path / "Lib" / "site-packages"}
+    assert set(LocalPackageResolver.find_package_dirs(path)) == expect
+
+
+@pytest.mark.skipif(
+    platform.system() == "Windows", reason="Not relevant to Windows virtual environment"
+)
 @pytest.mark.parametrize(
     "subdir", [pytest.param(d, id=f"venv:{d}") for d in env_subdirs]
 )
@@ -56,6 +75,9 @@ def test_find_package_dirs__various_paths_in_venv(tmp_path, subdir):
     assert set(LocalPackageResolver.find_package_dirs(path)) == expect
 
 
+@pytest.mark.skipif(
+    platform.system() == "Windows", reason="Not relevant to Windows virtual environment"
+)
 @pytest.mark.parametrize(
     "subdir", [pytest.param(d, id=f"poetry2nix:{d}") for d in env_subdirs]
 )
@@ -72,6 +94,9 @@ def test_find_package_dirs__various_paths_in_poetry2nix_env(write_tmp_files, sub
     assert set(LocalPackageResolver.find_package_dirs(path)) == expect
 
 
+@pytest.mark.skipif(
+    platform.system() == "Windows", reason="Not relevant to Windows virtual environment"
+)
 @pytest.mark.parametrize(
     "subdir", [pytest.param(d, id=f"pep582:{d}") for d in pep582_subdirs]
 )
@@ -87,6 +112,9 @@ def test_find_package_dirs__various_paths_in_pypackages(write_tmp_files, subdir)
     assert set(LocalPackageResolver.find_package_dirs(path)) == expect
 
 
+@pytest.mark.skipif(
+    platform.system() == "Windows", reason="Not relevant to Windows virtual environment"
+)
 @pytest.mark.parametrize(
     "subdir",
     [pytest.param(d, id=f"pep582:{d}") for d in pep582_subdirs]