[self-tests] few tests fail against setuptools 68.0.0

[stanislavlevin]

setuptools_scm tests suite fails againt setuptools 68.0.0 with:

FAILED testing/test_integration.py::test_pyproject_support_with_git[pyproject.project]
FAILED testing/test_integration.py::test_pretend_version_named_pyproject_integration[pyproject.project]

    Traceback (most recent call last):
      File "/usr/src/tmp/pytest-of-builder/pytest-0/test_pyproject_support_with_gi3/wd/setup.py", line 1, in <module>
        __import__('setuptools').setup()
      File "/usr/lib64/python3/site-packages/setuptools/__init__.py", line 107, in setup
        return distutils.core.setup(**attrs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/usr/lib64/python3/site-packages/setuptools/_distutils/core.py", line 159, in setup
        dist.parse_config_files()
      File "/usr/lib64/python3/site-packages/setuptools/dist.py", line 899, in parse_config_files
        pyprojecttoml.apply_configuration(self, filename, ignore_option_errors)
      File "/usr/lib64/python3/site-packages/setuptools/config/pyprojecttoml.py", line 66, in apply_configuration
        config = read_configuration(filepath, True, ignore_option_errors, dist)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/usr/lib64/python3/site-packages/setuptools/config/pyprojecttoml.py", line 128, in read_configuration
        validate(subset, filepath)
      File "/usr/lib64/python3/site-packages/setuptools/config/pyprojecttoml.py", line 55, in validate
        raise ValueError(f"{error}\n{summary}") from None
    ValueError: invalid pyproject.toml config: `project`.
    configuration error: `project` must contain ['version'] properties

setuptools 68.0.0 introduced many breaking changes https://setuptools.pypa.io/en/stable/history.html#v68-0-0

one of them:

pypa/setuptools#3948: Removed support for invalid pyproject.toml files. During the implementation of PEP 621, it was identified that some users were producing invalid files. As a transitional measure, the validation was relaxed for a few use cases. The grace period, however, came to an end.

pyproject.toml used in the test:

[project]
name='setuptools_scm_example'
[tool.setuptools_scm]

while according to today's specification https://packaging.python.org/en/latest/specifications/declaring-project-metadata/#specification

The only keys required to be statically defined are:

• name

The keys which are required but may be specified either statically or listed as dynamic are:

• version