Use importlib with python 3.5+

This fixes `python run.py ci` under python 3.12.

dev/coverage.py

@@ -4,7 +4,6 @@
 import cgi
 import codecs
 import coverage
-import imp
 import json
 import os
 import unittest
@@ -33,6 +32,11 @@
 else:
     Pattern = re.Pattern
 
+if sys.version_info < (3, 5):
+    import imp
+else:
+    import importlib
+
 
 def run(ci=False):
     """
@@ -103,8 +107,19 @@ def _load_package_tests(name):
     if not os.path.exists(package_dir):
         return []
 
-    tests_module_info = imp.find_module('tests', [package_dir])
-    tests_module = imp.load_module('%s.tests' % name, *tests_module_info)
+    if sys.version_info < (3, 5):
+        tests_module_info = imp.find_module('tests', [package_dir])
+        tests_module = imp.load_module('%s.tests' % name, *tests_module_info)
+    else:
+        loader_details = (
+            importlib.machinery.SourceFileLoader,
+            importlib.machinery.SOURCE_SUFFIXES
+        )
+        finder = importlib.machinery.FileFinder(package_dir, loader_details)
+        spec = finder.find_spec('tests')
+        test_module = importlib.util.module_from_spec(spec)
+        sys.modules['%s.tests' % name] = test_module
+        spec.loader.exec_module(test_module)
     return tests_module.test_classes()