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)

pyproject.toml

@@ -58,6 +58,7 @@ xdoctest = "*"
 coverage = {version = "*", extras = ["toml"]}
 pytest-timeout = "^2"
 pytest-freezer = "^0.4"
+mypy = "1.9.0"
 
 [tool.poetry.extras]
 docs = ["sphinx", "sphinx_rtd_theme", "sphinxcontrib-programoutput", "myst-parser", "docutils"]
@@ -138,3 +139,19 @@ convention = "pep257"
     "D100",
     "D103",
 ]
+
+[tool.mypy]
+warn_unused_configs = true  # warns if overrides sections unused/mis-spelled
+
+[[tool.mypy.overrides]]
+module = [ "kasa.tests.*", "devtools.*" ]
+disable_error_code = "annotation-unchecked"
+
+[[tool.mypy.overrides]]
+module = [
+    "devtools.bench.benchmark",
+    "devtools.parse_pcap",
+    "devtools.perftest",
+    "devtools.create_module_fixtures"
+]
+disable_error_code = "import-not-found,import-untyped"