Skip $PATH entries we cannot check rather than dying with PermissionError

[hroncok]

On Fedora CI, I used runuser to get rid of root privileges before testing virtualenv.

The invocation I used did not clear the root's $PATH and as a result, one of the entries in $PATH was /root/.local/bin.
But /root/ does not allow other users to browse (execute, read).

That lead to an unhanded PermissionError.

When this happens, the $PATH entry is now skipped as if it did not exist.

As there might be other reasons we cannot check if the $PATH entry exists, I decided to suppress all OSError types.

For clarity, here is the Traceback I was getting:

# runuser testuser -c 'virtualenv --with-traceback --python pypy3.10 venv'
Traceback (most recent call last):
  File "/usr/bin/virtualenv", line 8, in <module>
    sys.exit(run_with_catch())
             ~~~~~~~~~~~~~~^^
  File "/usr/lib/python3.13/site-packages/virtualenv/__main__.py", line 56, in run_with_catch
    run(args, options, env)
    ~~~^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/virtualenv/__main__.py", line 18, in run
    session = cli_run(args, options, env)
  File "/usr/lib/python3.13/site-packages/virtualenv/run/__init__.py", line 31, in cli_run
    of_session = session_via_cli(args, options, setup_logging, env)
  File "/usr/lib/python3.13/site-packages/virtualenv/run/__init__.py", line 49, in session_via_cli
    parser, elements = build_parser(args, options, setup_logging, env)
                       ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/virtualenv/run/__init__.py", line 77, in build_parser
    parser._interpreter = interpreter = discover.interpreter  # noqa: SLF001
                                        ^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/virtualenv/discovery/discover.py", line 41, in interpreter
    self._interpreter = self.run()
                        ~~~~~~~~^^
  File "/usr/lib/python3.13/site-packages/virtualenv/discovery/builtin.py", line 58, in run
    result = get_interpreter(python_spec, self.try_first_with, self.app_data, self._env)
  File "/usr/lib/python3.13/site-packages/virtualenv/discovery/builtin.py", line 75, in get_interpreter
    for interpreter, impl_must_match in propose_interpreters(spec, try_first_with, app_data, env):
                                        ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/virtualenv/discovery/builtin.py", line 147, in propose_interpreters
    for pos, path in enumerate(get_paths(env)):
                     ~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/virtualenv/discovery/builtin.py", line 169, in get_paths
    if p.exists():
       ~~~~~~~~^^
  File "/usr/lib64/python3.13/pathlib/_abc.py", line 450, in exists
    self.stat(follow_symlinks=follow_symlinks)
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.13/pathlib/_local.py", line 515, in stat
    return os.stat(self, follow_symlinks=follow_symlinks)
           ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 13] Permission denied: '/root/.local/bin'

Thanks for contributing, make sure you address all the checklists (for details on how see development documentation)

• ran the linter to address style issues (tox -e fix)
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• ensured there are test(s) validating the fix
• added news fragment in docs/changelog folder
• updated/extended the documentation

[hroncok]

(I don't think the CI failures are related.)

[gaborbernat]

Can you put in another PR to fix that failure to unblock merging?

[hroncok]

I have no idea what's going on there.

[hroncok]

Thanks.