Add a built-in way to compare sequences ignoring order

What's the problem this feature will solve?

A convenient way to assert that two sequences contains the exact same elements regardless of their order.

Describe the solution you'd like

assert [1, 2, 3] == pytest.unordered([2, 1, 3])

For example, I could use it when order of elements are not part of the specification of a function:

# Per "Path.iterdir()" documentation: "The children are yielded in arbitrary order"
assert list(tmp_path.iterdir()) == pytest.unordered([tmp_path / "some_file.txt", tmp_path / "another_file.txt"])

Alternative Solutions

Sorting the sequence manually, using unittest.TestCase.assertCountEqual, using pytest-unordered plugin.

Additional context

This issue duplicates:

• https://github.com/pytest-dev/pytest/issues/5548
• https://github.com/pytest-dev/pytest/issues/7899

These tickets were closed with the suggestion to first create an external plugin and testing it during a few years. Following this, @utapyngo created the pytest-unordered plugin. It has been several years. I would like to bring back the suggestion of a built-in pytest.unordered() helper similar to pytest.approx() because I think pytest users would greatly benefit from it.

I don't think it opens the room for too many assertion helpers: with approx() and unordered() all main cases are covered. For comparison, here is the list of helpers provided by the Catch2 C++ testing library. Python provides many built-in functions to ease assertion, but unordered() is missing and is non-trivial.

What do you think?