Shutdown notebooks without any bonds

[ctrekker]

I am exporting notebooks with sliders enabled, but many (not all) of my notebooks exported with PlutoSliderServer have no sliders. Currently if sliders are enabled all notebook sessions are kept running, even if they have no bonds. To save on memory, could we shut these processes down? I've written some code that does this, but before submitting a PR I wanted to make sure that this is actually a behavior that makes sense. @fonsp

[ctrekker]

PS: in my case shutting down 10 non-interactive notebooks saved about 5 GB of memory!

[fonsp]

sounds good! i thought we already had this :)