Symbolic link components are no longer resolved in conftest paths.
This means that if a conftest appears twice in collection tree, using symlinks, it will be executed twice.
For example, given

    tests/real/conftest.py
    tests/real/test_it.py
    tests/link -> tests/real

running ``pytest tests`` now imports the conftest twice, once as ``tests/real/conftest.py`` and once as ``tests/link/conftest.py``.
This is a fix to match a similar change made to test collection itself in pytest 6.0 (see :pull:`6523` for details).