Remove implied binder support

[lagru]

The last tutorial requires that the Ipython process runs on the users machine itself to display Napari. So we probably don't support binder for this tutorial? Then it seems useful not to indicate so to users.

[jni]

@lagru actually, unless something has broken, binder does work, thanks to jupyter desktop, and what we should do is (a) test and (b) restore those instructions!

https://github.com/napari/napari-workshop-template/blob/main/napari-workshops/docs/launching_binder.md

I'm gonna give it a go now.

[jni]

not a good start 😂

[jni]

Whoop whoop! 😊 So cool. It doesn't really show off napari very well (super slow response), but it friggin works.

[jni]

Well, no time to fix it, so I'm going to merge this for now — we can add back in later if required.