Fix importlib_metadata.entry_points attribute error by updating flake8

[IniterWorker]

Description of the problem

 _load_entrypoint_plugins
    eps = importlib_metadata.entry_points().get(self.namespace, ())
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'EntryPoints' object has no attribute 'get'

Description of the solution

Bump flake8 pre-commit hook version from 3.9.1 to 7.0.0.