chore: increase minimum Python to 3.9 (#19)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: bdraco

.pre-commit-config.yaml

@@ -40,7 +40,7 @@ repos:
     rev: v3.6.0
     hooks:
       - id: pyupgrade
-        args: [--py37-plus]
+        args: [--py39-plus]
   - repo: https://github.com/PyCQA/isort
     rev: 5.12.0
     hooks:

build_ext.py

@@ -4,7 +4,7 @@
 import os
 from distutils.command.build_ext import build_ext
 from os.path import join
-from typing import Any, Dict
+from typing import Any
 
 try:
     from setuptools import Extension
@@ -26,7 +26,7 @@ def build_extensions(self) -> None:
             super().build_extensions()
 
 
-def build(setup_kwargs: Dict[Any, Any]) -> None:
+def build(setup_kwargs: dict[Any, Any]) -> None:
     if os.environ.get("SKIP_CYTHON", False):
         return
     try: