Leakage of NUMBER option out of docstring scope

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This was originally noted in #9892, but there is a more targeted MRE here.

MRE

Running pytest --doctest-modules test_x.py with x=1, 2 or 3 results in the following pattern of failing and passing tests. The test inside test_wo_number incorrectly passes only on the cases (test_1.py and test_2.py) where a failing test that uses NUMBER (test_w_off_by_2_number) also exists in the same module. This leakage does not occur when there are tests that pass that utilize NUMBER (test_3.py)

# test_1.py
def test_w_number():
    """
    Correctly Passes

    Examples
    --------
    >>> 1.  # doctest: +NUMBER
    0.
    """

def test_w_off_by_2_number():
    """
    Correctly Fails

    Examples
    --------
    >>> 0.  # doctest: +NUMBER
    2.
    """

def test_wo_number():
    """
    Incorrectly Passes

    Examples
    --------
    >>> 1.
    0.
    """

# test_2.py
def test_w_off_by_2_number():
    """
    Correctly Fails

    Examples
    --------
    >>> 0.  # doctest: +NUMBER
    2.
    """


def test_wo_number():
    """
    Incorrectly Passes

    Examples
    --------
    >>> 1.
    0.
    """

# test_3.py
def test_w_number():
    """
    Correctly Passes

    Examples
    --------
    >>> 1.  # doctest: +NUMBER
    0.
    """

def test_wo_number():
    """
    Correctly Fails

    Examples
    --------
    >>> 1.
    0.
    """

pip list

Package    Version
---------- -------
attrs      21.4.0
iniconfig  1.1.1
numpy      1.22.3
packaging  21.3
pip        22.0.4
pluggy     1.0.0
py         1.11.0
pyparsing  3.0.8
pytest     7.1.2
setuptools 41.2.0
tomli      2.0.1

system version

CentOS 7.9

Reproduce the issue with pytest --doctest-modules test_x.py using the three MRE module variants and focus on doctest handling of the NUMBER option. Verify that an option used in one docstring does not affect another, and that the no-option example in test_wo_number fails as expected.