Disable no-member check in pylint

This is already checked by `mypy`, and `pylint` is not as smart as `mypy`
to understand types, so it suffers from some false positives (for
example after asserting that an object `isinstance` of a type, `pylint`
still complains that the object don't have the attributes of the type).

Signed-off-by: Leandro Lucarella <luca-frequenz@llucax.com>

pyproject.toml

@@ -142,6 +142,8 @@ disable = [
   "line-too-long",
   "unused-variable",
   "unnecessary-lambda-assignment",
+  # Checked by mypy
+  "no-member",
 ]
 
 [tool.pytest.ini_options]