BUG, MAINT: Fix `arrows=True` parameter for `nx.draw_networkx_edges` in `plotting.draw_diagrams()` about kda

[nawtrey]

According to the source code, the warning will be raised if any of the following parameters are not met when arrows=False:

    if use_linecollection and any(
        [
            arrowstyle is not None,
            arrowsize != 10,
            connectionstyle != "arc3",
            min_source_margin != 0,
            min_target_margin != 0,
        ]

so the solution will have to set all of these back to the default for undirected graphs (i.e. partial diagrams).

Assuming we only use nx.is_directed() as the switch for handling these cases, that means that we will lose the functionality to generate undirected variants of directed graphs. This is probably "okay" for now since we generally draw undirected graphs with fancy arrows since they are a more accurate representation of the graph. If this is desired for something like a flux diagram, we may have to find a way to specify this manually, possibly by adding a new parameter to draw_diagrams(), but again this is not something in common use.