[networkx] Accept a Callable as relabel_nodes mapping (#16552)

Author: Cherith1222

stubs/networkx/networkx/relabel.pyi

@@ -1,4 +1,4 @@
-from collections.abc import Hashable, Mapping
+from collections.abc import Callable, Hashable, Mapping
 from typing import Literal, TypeVar, overload
 
 from networkx.classes.digraph import DiGraph
@@ -13,13 +13,15 @@ _Y = TypeVar("_Y", bound=Hashable)
 __all__ = ["convert_node_labels_to_integers", "relabel_nodes"]
 
 @overload
-def relabel_nodes(G: MultiDiGraph[_X], mapping: Mapping[_X, _Y], copy: bool = True) -> MultiDiGraph[_X | _Y]: ...
+def relabel_nodes(
+    G: MultiDiGraph[_X], mapping: Mapping[_X, _Y] | Callable[[_X], _Y], copy: bool = True
+) -> MultiDiGraph[_X | _Y]: ...
 @overload
-def relabel_nodes(G: DiGraph[_X], mapping: Mapping[_X, _Y], copy: bool = True) -> DiGraph[_X | _Y]: ...
+def relabel_nodes(G: DiGraph[_X], mapping: Mapping[_X, _Y] | Callable[[_X], _Y], copy: bool = True) -> DiGraph[_X | _Y]: ...
 @overload
-def relabel_nodes(G: MultiGraph[_X], mapping: Mapping[_X, _Y], copy: bool = True) -> MultiGraph[_X | _Y]: ...
+def relabel_nodes(G: MultiGraph[_X], mapping: Mapping[_X, _Y] | Callable[[_X], _Y], copy: bool = True) -> MultiGraph[_X | _Y]: ...
 @overload
-def relabel_nodes(G: Graph[_X], mapping: Mapping[_X, _Y], copy: bool = True) -> Graph[_X | _Y]: ...
+def relabel_nodes(G: Graph[_X], mapping: Mapping[_X, _Y] | Callable[[_X], _Y], copy: bool = True) -> Graph[_X | _Y]: ...
 
 @_dispatchable
 def convert_node_labels_to_integers(