Test failures with Black >=24.2

[akaihola]

If Black 24.2 or newer is installed, the test suite has multiple errors

To Reproduce
Steps to reproduce the behavior:

1. Clone this repository: git clone https://github.com/akaihola/darker.git
2. Do an editable install: cd darker ; pip install -e . black==24.2.0
3. Run tests: pytest
4. See test errors

Expected behavior
All tests should pass

Some failing tests

• test_command_line.py:test_parse_command_line_config_src:
  SystemExit: 2 with pytest: error: the following arguments are required: PATH\n
• test_command_line.py:test_parse_command_line_config_location_specified:
  args.lint == [], expected "pylint" when argv=["."] (first test case)
• test_command_line.py:test_parse_command_line_config_location_specified:
  args.lint == [], expected "flake8" when argv=["./subdir/"] (second test case)
• test_config.py:test_load_config:
  load_config() returns {'config': 'no_pyp'}, expected {'config': 'has_pyp'} when cwd="has_pyp" or "has_pyp/lvl1" (cases no. 5 & 6)
• test_config.py:test_load_config:
  load_config() returns {'config': 'no_pyp'}, expected {'config': 'has_pyp'} when pwd and srcs point to "has_pyp/lvl1/l1.py" (cases no. 19–22)
• test_config.py:test_load_config:
  load_config() returns {'config': 'no_pyp'}, expected lots of options when srcs=["full_example/full.py"] (case no. 23)
• test_config.py:test_load_config:
  load_config() returns {'config': 'no_pyp'}, expected {'stdout': True} when srcs=['stdout_example/dummy.py'](case no. 24)
• test_highlighting.py:test_should_use_color_pygments:
  should_use_color() returns True, expected False when pyproject_toml_color = 'color = false', tty = True, config_from_env_and_argv = None
• test_highlighting.py:test_should_use_color_pygments:
  should_use_color() returns False, expected True when pyproject_toml_color = 'color = true ', tty = False, config_from_env_and_argv = None
• test_import_sorting.py:test_isort_config:
  does not wrap the import at all when settings_file=None