pytest support with the next pytest release

[15r10nk]

I fixed the source positions in pytest which will allow executing to find the correct nodes (if used with the next pytest release).

pytest-dev/pytest#12815

The only thing which seems to be missing now is to fix the tests in executing.

❯ pytest
============================================================================================================= test session starts =============================================================================================================
platform linux -- Python 3.12.6, pytest-8.4.0.dev100+g5c25c5929, pluggy-1.5.0
rootdir: /home/frank/projects/executing
configfile: pyproject.toml
collected 209 items                                                                                                                                                                                                                           

tests/test_ipython.py ..                                                                                                                                                                                                                [  0%]
tests/test_main.py ..................ss...............................................................................................................................................................sssssssssssssss.                  [ 94%]
tests/test_pytest.py .....F......                                                                                                                                                                                                       [100%]

================================================================================================================== FAILURES ===================================================================================================================
___________________________________________________________________________________________________________ test_exception_catching ___________________________________________________________________________________________________________

    def test_exception_catching():
        frame = inspect.currentframe()
    
        executing.executing.TESTING = True  # this is already the case in all other tests
        # Sanity check that this operation usually raises an exception.
        # This actually depends on executing not working in the presence of pytest.
        with pytest.raises((NotOneValueFound, KnownIssue)):
>           assert Source.executing(frame).node is None
E           AssertionError: assert <ast.Call object at 0x7f7999d49390> is None
E            +  where <ast.Call object at 0x7f7999d49390> = <executing.executing.Executing object at 0x7f799a0a00b0>.node
E            +    where <executing.executing.Executing object at 0x7f799a0a00b0> = executing(<frame at 0x7f799a2420e0, file '/home/frank/projects/executing/tests/test_pytest.py', line 131, code test_exception_catching>)
E            +      where executing = Source.executing

tests/test_pytest.py:131: AssertionError
============================================================================================================== warnings summary ===============================================================================================================
tests/test_main.py::test_small_samples[4851dc1b626a95e97dbe0c53f96099d165b755dd1bd552c6ca771f7bca6d30f5.py]
  /home/frank/projects/executing/tests/small_samples/4851dc1b626a95e97dbe0c53f96099d165b755dd1bd552c6ca771f7bca6d30f5.py:16: SyntaxWarning: "is" with 'int' literal. Did you mean "=="?
    if 1 < 1 > 1 == 1 >= 1 <= 1 != 1 in 1 not in 1 is 1 is not 1:

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================================================================================================== short test summary info ===========================================================================================================
FAILED tests/test_pytest.py::test_exception_catching - AssertionError: assert <ast.Call object at 0x7f7999d49390> is None
============================================================================================ 1 failed, 191 passed, 17 skipped, 1 warning in 7.26s =============================================================================================