importlib.metadata test fails on Windows if symlinks aren't allowed

[encukou]

From the AMD64 Windows11 Refleaks 3.x buildbot:

test_packages_distributions_symlinked_top_level (test.test_importlib.test_main.PackagesDistributionsTest.test_packages_distributions_symlinked_top_level)
Distribution is resolvable from a simple top-level symlink in RECORD. ... ERROR
======================================================================
ERROR: test_packages_distributions_symlinked_top_level (test.test_importlib.test_main.PackagesDistributionsTest.test_packages_distributions_symlinked_top_level)
Distribution is resolvable from a simple top-level symlink in RECORD.
----------------------------------------------------------------------
Traceback (most recent call last):
  File "b:\uildarea\3.x.ware-win11.refleak\build\Lib\test\test_importlib\test_main.py", line 424, in test_packages_distributions_symlinked_top_level
    fixtures.build_files(files, self.site_dir)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "b:\uildarea\3.x.ware-win11.refleak\build\Lib\test\test_importlib\_path.py", line 70, in build
    create(contents, _ensure_tree_maker(prefix) / name)
    ~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "b:\uildarea\3.x.ware-win11.refleak\build\Lib\functools.py", line 911, in wrapper
    return dispatch(args[0].__class__)(*args, **kw)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "b:\uildarea\3.x.ware-win11.refleak\build\Lib\test\test_importlib\_path.py", line 91, in _
    path.symlink_to(content)
    ~~~~~~~~~~~~~~~^^^^^^^^^
  File "b:\uildarea\3.x.ware-win11.refleak\build\Lib\pathlib\__init__.py", line 806, in symlink_to
    os.symlink(target, self, target_is_directory)
    ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [WinError 1314] A required privilege is not held by the client: '.symlink.target' -> 'b:\\uildworker_temp\\test_python_sby1_qjd\\tmp16dtmklg\\symlinked'

The test needs to be skipped when symlinks are not supported.

Linked PRs

• gh-114107: Fix importlib.metadata symlink test if symlinks aren't supported #114108
• gh-114107: test.pythoninfo logs Windows Developer Mode #114121
• [3.11] gh-114107: test.pythoninfo logs Windows Developer Mode (GH-114121) #114128
• [3.12] gh-114107: test.pythoninfo logs Windows Developer Mode (GH-114121) #114129

[encukou]

This breaks a stable buildbot of a tier 1 platform. Per PEP-11, buildbot failures a any breakage should be fixed or reverted immediately.

I plan to skip the test with a test.support helper; later we can find a fix more compatible with the importlib_resources external repo.

[vstinner]

On python/buildmaster-config#454 I asked how to know if the Windows Developer Mode is enabled or not. I wrote #114121 which reads a registry value to log the state in test.pythoninfo.