Enable testing with Python 3.11 - #9511

    def get_resource_reader(self, name: str) -> importlib.abc.TraversableResources:  # type: ignore
        if sys.version_info < (3, 11):
            from importlib.readers import FileReader
        else:
>           from importlib.resources.readers import FileReader
E           ModuleNotFoundError: No module named 'importlib.resources.readers'; 'importlib.resources' is not a package

platform linux -- Python 3.11.0a5, pytest-7.1.0.dev220+g64f943958, pluggy-1.0.0

    def test_idmaker_enum(self) -> None:
        enum = pytest.importorskip("enum")
        e = enum.Enum("Foo", "one, two")
        result = IdMaker(
            ("a", "b"), [pytest.param(e.one, e.two)], None, None, None, None
        ).make_unique_parameterset_ids()
        if sys.version_info >= (3, 11):
>           assert result == ["one-two"]
E           AssertionError: assert ['Foo.one-Foo.two'] == ['one-two']
E             At index 0 diff: 'Foo.one-Foo.two' != 'one-two'
E             Use -v to get the full diff

    def test_run_result_repr() -> None:
        outlines = ["some", "normal", "output"]
        errlines = ["some", "nasty", "errors", "happened"]
    
        # known exit code
        r = pytester_mod.RunResult(1, outlines, errlines, duration=0.5)
        if sys.version_info >= (3, 11):
>           assert (
                repr(r) == "<RunResult ret=TESTS_FAILED len(stdout.lines)=3"
                " len(stderr.lines)=4 duration=0.50s>"
            )
E           AssertionError: assert '<RunResult r...ration=0.50s>' == '<RunResult r...ration=0.50s>'
E             - <RunResult ret=TESTS_FAILED len(stdout.lines)=3 len(stderr.lines)=4 duration=0.50s>
E             ?                ^^^^^^^^^^^^
E             + <RunResult ret=1 len(stdout.lines)=3 len(stderr.lines)=4 duration=0.50s>
E             ?