Fix compat with SciMLBase 2.11

[hexaeder]

https://github.com/SciML/SymbolicIndexingInterface.jl

is the way to go to access symbols moving forward. would resolve the restriction introduced in #131

[Datseris]

Hi @hexaeder can you please tell me how you learned of this package? I am trying to follow this as I also use symbolic indexing but I haven't heard of this package yet. Are there some specific channels you follow? E.g., this isn't posted in diffeq-bridged on slack.

[hexaeder]

Well nothing of that sort, I just realized that it broke my docs in GraphMakie where I use NetworkDynamics and I was able to track it down to this SciMLBase-PR which altered the struct definition 3 days ago and asked there... Chris also posted a link to the docs of the new package there.

I think it's inevitable, the core mechanism of NetworkDynamics was written many years ago when the SciML ecosystem was in a completely different shape. Luckily next year we'll have funding to do a proper rework and hopefully get rid of those kind of hacks :)

[hexaeder]

fixed in #140