DOC: sparse.csgraph.dijkstra: add warning for directed=False behaviour

[bharatr21]

Reference issue

Closes #20509 (Mentioned in #18688 as well?)

What does this implement/fix?

Adds a warning so the user can refer to the notes stating that Dijkstra isn't expected to work correctly under certain conditions when directed=False

Additional information

None

[lucascolley]

@bdpedigo does this look good to you?

[j-bowhay]

For future reference, for documentation-only changes please try to save compute resources by adding [docs only] to the end of your commit message as per https://docs.scipy.org/doc/scipy/dev/contributor/continuous_integration.html#skipping

[bharatr21]

For future reference, for documentation-only changes please try to save compute resources by adding [docs only] to the end of your commit message as per https://docs.scipy.org/doc/scipy/dev/contributor/continuous_integration.html#skipping

My apologies, I missed that while going through https://docs.scipy.org/doc/scipy/dev/contributor/rendering_documentation.html#contributing-docs because it was under a "Note", is there a way to make it more prominent or a part of the regular contributing workflow?

[bdpedigo]

@bdpedigo does this look good to you?

works for me!

[j-bowhay]

Thanks @bharatr21