Update type-hint syntax

This gets rid of some errors from the pyupgrade pre-commit hook.

Author: jsf9k

src/cyhy_runner/__init__.py

@@ -1,12 +1,9 @@
 """The Cyber Hygiene job runner."""
 
-# Standard Python Libraries
-from typing import List
-
 # We disable a Flake8 check for "Module imported but unused (F401)" here because
 # although this import is not directly used, it populates the value
 # package_name.__version__, which is used to get version information about this
 # Python package.
 from ._version import __version__  # noqa: F401
 
-__all__: List[str] = []
+__all__: list[str] = []

src/cyhy_runner/cyhy_runner.py

@@ -25,7 +25,6 @@
 import subprocess  # nosec
 import sys
 import time
-from typing import Set
 
 # Third-Party Libraries
 import daemon
@@ -51,7 +50,7 @@
 
 logger = logging.getLogger(__name__)
 
-running_dirs: Set[str] = set()
+running_dirs: set[str] = set()
 processes = []
 IS_RUNNING = True