mypy: Add no_incremental option

This option avoids using a cache. It is slower but prevents some issues
with `mypy` giving different results on different runs (typically
complaining about some `type: ignore[issue]` not being used but when
removing it complaining about an `issue` again.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

noxfile.py

@@ -3,6 +3,10 @@
 
 """Configuration file for nox."""
 
-from frequenz.repo.config import RepositoryType, nox
+from frequenz.repo.config import nox
+from frequenz.repo.config.nox import default
 
-nox.configure(RepositoryType.LIB)
+config = default.lib_config.copy()
+config.opts.mypy = []  # Set in pyproject.toml
+
+nox.configure(config)

pyproject.toml

@@ -135,6 +135,13 @@ testpaths = ["tests", "src"]
 asyncio_mode = "auto"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 
+[tool.mypy]
+explicit_package_bases = true
+namespace_packages = true
+no_incremental = true
+packages = ["frequenz.sdk"]
+strict = true
+
 [[tool.mypy.overrides]]
 module = [
   "async_solipsism",