replace some typing.* constructs with native ones

src/capport/config.py

@@ -3,23 +3,22 @@ from __future__ import annotations
 import dataclasses
 import logging
 import os.path
-import typing
 
 import yaml
 
 
-_cached_config: typing.Optional[Config] = None
+_cached_config: Config | None = None
 _logger = logging.getLogger(__name__)
 
 
 @dataclasses.dataclass
 class Config:
     _source_filename: str
-    controllers: typing.List[str]
-    server_names: typing.List[str]
+    controllers: list[str]
+    server_names: list[str]
     comm_secret: str
     cookie_secret: str
-    venue_info_url: typing.Optional[str]
+    venue_info_url: str | None
     session_timeout: int  # in seconds
     api_port: int
     controller_port: int
@@ -27,7 +26,7 @@ class Config:
     debug: bool
 
     @staticmethod
-    def load_default_once(filename: typing.Optional[str] = None) -> Config:
+    def load_default_once(filename: str | None = None) -> Config:
         global _cached_config
         if not _cached_config:
             _cached_config = Config.load(filename)
@@ -38,7 +37,7 @@ class Config:
         return _cached_config
 
     @staticmethod
-    def load(filename: typing.Optional[str] = None) -> Config:
+    def load(filename: str | None = None) -> Config:
         if filename is None:
             for name in ('capport.yaml', '/etc/capport.yaml'):
                 if os.path.exists(name):