Split up Windows tests relying on urlunparse behaviour

There was a behavioural change to `urllib.parse.urlunparse`[1] that
affects some of our tests on Windows. With the understanding that the
new behaviour is indeed desired, split up some tests relying on this
behaviour depending on the version of Python.

This currently affects only 3.12 and 3.13 but there are other backports
for that change in review upstream, so we'll likely need to update this
in the future.

[1] python/cpython#113563

tests/unit/test_collector.py

@@ -3,6 +3,7 @@
 import logging
 import os
 import re
+import sys
 import uuid
 from pathlib import Path
 from textwrap import dedent
@@ -377,33 +378,13 @@ def test_clean_url_path_with_local_path(path: str, expected: str) -> None:
             "git+https://example.com/repo.git@at%40 space#egg=my-package-1.0",
             "git+https://example.com/repo.git@at%40%20space#egg=my-package-1.0",
         ),
-        # URL with Windows drive letter. The `:` after the drive
-        # letter should not be quoted. The trailing `/` should be
-        # removed.
-        pytest.param(
-            "file:///T:/path/with spaces/",
-            "file:///T:/path/with%20spaces",
-            marks=pytest.mark.skipif(
-                "sys.platform != 'win32' or "
-                "sys.version_info == (3, 13, 0, 'beta', 2)"
-            ),
-        ),
         # URL with Windows drive letter, running on non-windows
         # platform. The `:` after the drive should be quoted.
         pytest.param(
             "file:///T:/path/with spaces/",
             "file:///T%3A/path/with%20spaces/",
             marks=pytest.mark.skipif("sys.platform == 'win32'"),
         ),
-        # Test a VCS URL with a Windows drive letter and revision.
-        pytest.param(
-            "git+file:///T:/with space/[email protected]#egg=my-package-1.0",
-            "git+file:///T:/with%20space/[email protected]#egg=my-package-1.0",
-            marks=pytest.mark.skipif(
-                "sys.platform != 'win32' or "
-                "sys.version_info == (3, 13, 0, 'beta', 2)"
-            ),
-        ),
         # Test a VCS URL with a Windows drive letter and revision,
         # running on non-windows platform.
         pytest.param(
@@ -417,6 +398,66 @@ def test_ensure_quoted_url(url: str, clean_url: str) -> None:
     assert _ensure_quoted_url(url) == clean_url
 
 
+# versions containing fix/backport from https://github.com/python/cpython/pull/113563
+has_new_urlun_behaviour = (
+    # https://github.com/python/cpython/commit/387ff96e95b9f8a8cc7e646523ba3175b1350669
+    (sys.version_info[:2] == (3, 12) and sys.version_info >= (3, 12, 4))
+    or
+    # https://github.com/python/cpython/commit/872000606271c52d989e53fe4cc9904343d81855
+    (sys.version_info[:2] == (3, 13) and sys.version_info >= (3, 13, 0, "beta", 3))
+)
+
+
+@pytest.mark.skipif(
+    sys.platform != "win32" or has_new_urlun_behaviour,
+    reason="testing windows behaviour on older CPython",
+)
+@pytest.mark.parametrize(
+    ("url", "clean_url"),
+    (
+        (
+            # URL with Windows drive letter. The `:` after the drive
+            # letter should not be quoted. The trailing `/` should be
+            # removed.
+            "file:///T:/path/with spaces/",
+            "file:///T:/path/with%20spaces",
+        ),
+        (
+            # Test a VCS URL with a Windows drive letter and revision.
+            "git+file:///T:/with space/[email protected]#egg=my-package-1.0",
+            "git+file:///T:/with%20space/[email protected]#egg=my-package-1.0",
+        ),
+    ),
+)
+def test_ensure_quoted_url_windows_old(url: str, clean_url: str) -> None:
+    assert _ensure_quoted_url(url) == clean_url
+
+
+@pytest.mark.skipif(
+    sys.platform != "win32" or not has_new_urlun_behaviour,
+    reason="testing windows behaviour on newer cpython",
+)
+@pytest.mark.parametrize(
+    ("url", "clean_url"),
+    (
+        (
+            # URL with Windows drive letter. The `:` after the drive
+            # letter should not be quoted. The trailing `/` should be
+            # removed.
+            "file:///T:/path/with spaces/",
+            "file://///T:/path/with%20spaces",
+        ),
+        (
+            # Test a VCS URL with a Windows drive letter and revision.
+            "git+file:///T:/with space/[email protected]#egg=my-package-1.0",
+            "git+file://///T:/with%20space/[email protected]#egg=my-package-1.0",
+        ),
+    ),
+)
+def test_ensure_quoted_url_windows_new(url: str, clean_url: str) -> None:
+    assert _ensure_quoted_url(url) == clean_url
+
+
 def _test_parse_links_data_attribute(
     anchor_html: str, attr: str, expected: Optional[str]
 ) -> Link: