Remove use of pkg_resources package (#3069)

openmc/lib/__init__.py

@@ -13,11 +13,10 @@ functions or objects in :mod:`openmc.lib`, for example:
 """
 
 from ctypes import CDLL, c_bool, c_int
+import importlib.resources
 import os
 import sys
 
-import pkg_resources
-
 
 # Determine shared-library suffix
 if sys.platform == 'darwin':
@@ -27,9 +26,8 @@ else:
 
 if os.environ.get('READTHEDOCS', None) != 'True':
     # Open shared library
-    _filename = pkg_resources.resource_filename(
-        __name__, f'libopenmc.{_suffix}')
-    _dll = CDLL(_filename)
+    _filename = importlib.resources.files(__name__) / f'libopenmc.{_suffix}'
+    _dll = CDLL(str(_filename))  # TODO: Remove str() when Python 3.12+
 else:
     # For documentation builds, we don't actually have the shared library
     # available. Instead, we create a mock object so that when the modules

pyproject.toml

@@ -46,7 +46,7 @@ docs = [
     "sphinxcontrib-svg2pdfconverter",
     "sphinx-rtd-theme==1.0.0"
 ]
-test = ["pytest", "pytest-cov", "colorama", "openpyxl"]
+test = ["packaging", "pytest", "pytest-cov", "colorama", "openpyxl"]
 vtk = ["vtk"]
 
 [project.urls]

tests/regression_tests/conftest.py

@@ -1,12 +1,12 @@
 import numpy as np
 import openmc
-from pkg_resources import parse_version
+from packaging.version import parse
 import pytest
 
 
 @pytest.fixture(scope='module', autouse=True)
 def numpy_version_requirement():
-    assert parse_version(np.__version__) >= parse_version("1.14"), \
+    assert parse(np.__version__) >= parse("1.14"), \
         "Regression tests require NumPy 1.14 or greater"