Configure mypy to run in virtual environment and fix resulting issues (#989)

For some time I've noticed that my IDE is reporting mypy errors that the
pre-commit hook is not picking up. This is because [mypy
mirror](https://github.com/pre-commit/mirrors-mypy) runs in an isolated
pre-commit environment which does not have dependencies installed and it
enables `--ignore-missing-imports` to avoid errors.

This is [advised against by
mypy](https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-library-stubs-or-py-typed-marker)
for obvious reasons:

> We recommend avoiding --ignore-missing-imports if possible: it’s
equivalent to adding a # type: ignore to all unresolved imports in your
codebase.

This PR configures the mypy pre-commit hook to run in the virtual
environment and addresses the additional errors identified as a result.
It also introduces a minimal mypy config into the `pyproject.toml`

[mypy errors identified without the fixes in this
PR](https://github.com/user-attachments/files/15896693/mypyerrors.txt)

kasa/tests/smart/modules/test_firmware.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import asyncio
 import logging
+from typing import TypedDict
 
 import pytest
 from pytest_mock import MockerFixture
@@ -71,7 +72,17 @@ async def test_firmware_update(
     assert fw
 
     upgrade_time = 5
-    extras = {"reboot_time": 5, "upgrade_time": upgrade_time, "auto_upgrade": False}
+
+    class Extras(TypedDict):
+        reboot_time: int
+        upgrade_time: int
+        auto_upgrade: bool
+
+    extras: Extras = {
+        "reboot_time": 5,
+        "upgrade_time": upgrade_time,
+        "auto_upgrade": False,
+    }
     update_states = [
         # Unknown 1
         DownloadState(status=1, download_progress=0, **extras),