Use new networkx type stubs from typeshed

Type stubs are not [officially available][1], so we use them instead of
instruct `mypy` to ignore type hints for the `networkx` module.

[1]: networkx/networkx#3988 (comment)

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

Author: llucax

pyproject.toml

@@ -72,6 +72,7 @@ dev-mypy = [
   "types-Markdown == 3.9.0.20250906",
   "types-protobuf == 6.32.1.20250918",
   "types-setuptools == 80.9.0.20250822",
+  "types-networkx == 3.5.0.20251106",
   # For checking the noxfile, docs/ script, and tests
   "frequenz-sdk[dev-mkdocs,dev-noxfile,dev-pytest]",
 ]
@@ -205,13 +206,7 @@ files = ["src", "tests", "examples", "benchmarks", "docs", "noxfile.py"]
 strict = true
 
 [[tool.mypy.overrides]]
-module = [
-  "async_solipsism",
-  "mkdocs_macros.*",
-  # The available stubs packages are outdated or incomplete (WIP/experimental):
-  # https://github.com/frequenz-floss/frequenz-sdk-python/issues/430
-  "networkx",
-]
+module = ["async_solipsism", "mkdocs_macros.*"]
 ignore_missing_imports = true
 
 [tool.setuptools_scm]

src/frequenz/sdk/microgrid/component_graph.py

@@ -369,7 +369,7 @@ def __init__(
             InvalidGraphError: If `components` and `connections` are not both `None`
                 and either of them is either `None` or empty.
         """
-        self._graph: nx.DiGraph = nx.DiGraph()
+        self._graph: nx.DiGraph[ComponentId] = nx.DiGraph()
 
         if components is None and connections is None:
             return
@@ -437,6 +437,7 @@ def connections(
         """
         matching_sources = _comp_ids_to_iter(matching_sources)
         matching_destinations = _comp_ids_to_iter(matching_destinations)
+        selection: Iterable[tuple[ComponentId, ComponentId]]
 
         match (matching_sources, matching_destinations):
             case (None, None):
@@ -536,7 +537,7 @@ def refresh_from(
         if issues:
             raise InvalidGraphError(f"Invalid component data: {', '.join(issues)}")
 
-        new_graph = nx.DiGraph()
+        new_graph: nx.DiGraph[ComponentId] = nx.DiGraph()
         new_graph.add_nodes_from(
             (component.id, {_DATA_KEY: component}) for component in components
         )