AIE-3321 fix importlib resources deprecation warnings

[jclerman]

Resolving importlib.resources warnings

Tests and usage of philters_lite generates warnings due to usage of deprecated interfaces from importlib.resources. To wit:

philter_lite/filters/filter_db.py:15
  /Users/jclerman/git/philter-lite/philter_lite/filters/filter_db.py:15: DeprecationWarning: read_text is deprecated. Use files() instead. Refer to https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy for migration advice.
    return tomllib.loads(resources.read_text(filters, "regex.toml"))

../../.pyenv/versions/3.11.10/lib/python3.11/importlib/resources/_legacy.py:80
minor linting fix
../../.pyenv/versions/3.11.10/lib/python3.11/importlib/resources/_legacy.py:80
../../.pyenv/versions/3.11.10/lib/python3.11/importlib/resources/_legacy.py:80
  /Users/jclerman/.pyenv/versions/3.11.10/lib/python3.11/importlib/resources/_legacy.py:80: DeprecationWarning: open_text is deprecated. Use files() instead. Refer to https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy for migration advice.
    with open_text(package, resource, encoding, errors) as fp:

philter_lite/filters/filter_db.py:19
  /Users/jclerman/git/philter-lite/philter_lite/filters/filter_db.py:19: DeprecationWarning: read_text is deprecated. Use files() instead. Refer to https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy for migration advice.
    return tomllib.loads(resources.read_text(filters, "regex_context.toml"))

philter_lite/filters/filter_db.py:23
  /Users/jclerman/git/philter-lite/philter_lite/filters/filter_db.py:23: DeprecationWarning: read_text is deprecated. Use files() instead. Refer to https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy for migration advice.
    return tomllib.loads(resources.read_text(filters, "set.toml"))

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

Here, switching to usage of the new interface to resolve those warnings (and avoid use of a deprecated interface).