Explicit note that tmpdir fixture is discouraged in favour of tmp_path #9937
Description
While https://docs.pytest.org/en/7.1.x/how-to/tmp_path.html#the-tmpdir-and-tmpdir-factory-fixtures` mentions "These days, prefer to use tmp_path and tmp_path_factory", it's quite hidden in the text.
I propose to announce this more loudly using a note admonition. Additionally the note admonition should be placed in the docstrings:
- https://docs.pytest.org/en/7.1.x/reference/reference.html?highlight=tmpdir#std-fixture-tmpdir
- https://docs.pytest.org/en/7.1.x/reference/reference.html?highlight=tmpdir#pytest.legacypath.LegacyTmpdirPlugin.tmpdir
The same holds for tmpdir_factory.