GraphMakie docs update

[vyudu]

Update docs and drop Graphviz dependency. Ran into an issue on my machine where ExpandTemplates was hanging for a really long time, so I changed some of the @example blocks to just ```julia, but it was still sort of hanging on the machine so not sure what's happening. In any case wanted to see how it did on the CI.

[isaacsas]

You need to also update all the places in the current docs where we show graphs to use the new code (preferably dynamically).

[isaacsas]

GLMakie tests are failing?

[vyudu]

seems something GLFW-related, happening in the docs build too. Will probably debug tomorrow

[isaacsas]

ok

[isaacsas]

Seems like somehow the plot from Makie is getting loaded now even in tutorials that don't use Makie for plotting?

[vyudu]

seems like it was because GLMakie is loaded in that @example block, added an explicit import to fix

[isaacsas]

You seem to be getting hit by the same NonlinearSolve related doc build error I was seeing. This seems to have just appeared in the last day or so.

[ChrisRackauckas]

Are you referring to the Cassette one? Has anyone upstreamed an issue to Cassette yet?

[isaacsas]

@vyudu maybe just comment out that tutorial for now so we can get this merged?

@ChrisRackauckas I don't know if anyone has upstreamed it -- I'm not sure anyone has investigated what is going on beyond seeing the doc build stack trace.

[vyudu]

I think this needs to merge after #1138 since I fix the other doc build error in that PR