Use tomllib/tomli for reading .toml configs

Use the built-in `tomllib` module in Python 3.11 and the modern `tomli`
package in older Python versions to read .toml configs instead of
the unmaintained and broken `toml` package.

Fixes #599
Fixes #600

requirements/runtime.txt

@@ -1,2 +1,2 @@
 snowballstemmer==1.2.1
-toml==0.10.2
+tomli==2.0.1; python_version < "3.11"

requirements/tests.txt

@@ -2,5 +2,4 @@ pytest==6.2.5
 mypy==0.930
 black==22.3
 isort==5.4.2
-types-toml
 types-setuptools

setup.py

@@ -8,7 +8,7 @@
     'snowballstemmer',
 ]
 extra_requirements = {
-    'toml': ['toml'],
+    'toml': ['tomli; python_version < "3.11"'],
 }
 
 

src/pydocstyle/config.py

@@ -4,6 +4,7 @@
 import itertools
 import operator
 import os
+import sys
 from collections import namedtuple
 from collections.abc import Set
 from configparser import NoOptionError, NoSectionError, RawConfigParser
@@ -13,10 +14,13 @@
 from .utils import __version__, log
 from .violations import ErrorRegistry, conventions
 
-try:
-    import toml
-except ImportError:  # pragma: no cover
-    toml = None  # type: ignore
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    try:
+        import tomli as tomllib
+    except ImportError:  # pragma: no cover
+        tomllib = None  # type: ignore
 
 
 def check_initialized(method):
@@ -59,15 +63,15 @@ def read(self, filenames, encoding=None):
         read_ok = []
         for filename in filenames:
             try:
-                with open(filename, encoding=encoding) as fp:
-                    if not toml:
+                with open(filename, "rb") as fp:
+                    if not tomllib:
                         log.warning(
                             "The %s configuration file was ignored, "
-                            "because the `toml` package is not installed.",
+                            "because the `tomli` package is not installed.",
                             filename,
                         )
                         continue
-                    self._config.update(toml.load(fp))
+                    self._config.update(tomllib.load(fp))
             except OSError:
                 continue
             if isinstance(filename, os.PathLike):