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/test_httpclient.py

@@ -38,7 +38,7 @@ from ..httpclient import HttpClient
         ),
         (Exception(), KasaException, "Unable to query the device: "),
         (
-            aiohttp.ServerFingerprintMismatch("exp", "got", "host", 1),
+            aiohttp.ServerFingerprintMismatch(b"exp", b"got", "host", 1),
             KasaException,
             "Unable to query the device: ",
         ),
@@ -84,7 +84,7 @@ async def test_httpclient_errors(mocker, error, error_raises, error_message, moc
     client = HttpClient(DeviceConfig(host))
     # Exceptions with parameters print with double quotes, without use single quotes
     full_msg = (
-        "\("  # type: ignore
+        re.escape("(")
         + "['\"]"
         + re.escape(f"{error_message}{host}: {error}")
         + "['\"]"