flake8-mock 0.4 fails with UnicodeDecodeError

[xqt]

flake8-mock fails with UnicodeDecodeError for Python 3.13 as follows:

C:\pwb\GIT\core>pre-commit run flake8 -a
flake8...................................................................Failed
- hook id: flake8
- exit code: 1

multiprocessing.pool.RemoteTraceback:
"""
Traceback (most recent call last):
  File "C:\Python\Python313\Lib\multiprocessing\pool.py", line 125, in worker
    result = (True, func(*args, **kwds))
                    ~~~~^^^^^^^^^^^^^^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\checker.py", line 82, in _mp_run
    ).run_checks()
      ~~~~~~~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\checker.py", line 526, in run_checks
    self.run_ast_checks()
    ~~~~~~~~~~~~~~~~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\checker.py", line 428, in run_ast_checks
    for line_number, offset, text, _ in runner:
                                        ^^^^^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8_mock.py", line 41, in run
    node_ast = file_to_check.read()
  File "C:\Python\Python313\Lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
           ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 1629: character maps to <undefined>
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Scripts\flake8.EXE\__main__.py", line 6, in <module>
    sys.exit(main())
             ~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\main\cli.py", line 23, in main
    app.run(argv)
    ~~~~~~~^^^^^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\main\application.py", line 198, in run
    self._run(argv)
    ~~~~~~~~~^^^^^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\main\application.py", line 187, in _run
    self.run_checks()
    ~~~~~~~~~~~~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\main\application.py", line 103, in run_checks
    self.file_checker_manager.run()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\checker.py", line 235, in run
    self.run_parallel()
    ~~~~~~~~~~~~~~~~~^^
  File "C:\Users\<redacted>\.cache\pre-commit\repo0n9yyvqp\py_env-python3\Lib\site-packages\flake8\checker.py", line 204, in run_parallel
    self.results = list(pool.imap_unordered(_mp_run, self.filenames))
                   ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python\Python313\Lib\multiprocessing\pool.py", line 873, in next
    raise value
UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 1629: character maps to <undefined>

btw flake8-mock-x2 works.