Check health fails for neovim v0.11 as `vim.health.report_start()` is removed

[bkp5190]

Reference: https://neovim.io/doc/user/deprecated.html#:~:text=health%23report_start%20vim.health.report_start()%20Use%20vim.health.start()%20instead.

[vandalt]

Duplicate of #23

[kamransoomro84]

It doesn't just appear to be checkhealth. Here's the error I get when I try to open an ipynb file:

Error executing vim.schedule lua callback: vim/_editor.lua:0: nvim_exec2()[1]..BufReadCmd Autocommands for "*.ipynb": Vim(append):Error executing lua callback: ...cal/share/nvim/lazy/jupytext.nvim/lua/jupytext/utils.lua:17: attempt to index field 'kernelspec' (a nil value)
stack traceback:
	...cal/share/nvim/lazy/jupytext.nvim/lua/jupytext/utils.lua:17: in function 'get_ipynb_metadata'
	...ocal/share/nvim/lazy/jupytext.nvim/lua/jupytext/init.lua:70: in function 'read_from_ipynb'
	...ocal/share/nvim/lazy/jupytext.nvim/lua/jupytext/init.lua:176: in function <...ocal/share/nvim/lazy/jupytext.nvim/lua/jupytext/init.lua:175>
	[C]: in function 'nvim_exec2'
	vim/_editor.lua: in function 'cmd'
	...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:115: in function 'jump'
	...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:36: in function <...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:35>
stack traceback:
	[C]: in function 'nvim_exec2'
	vim/_editor.lua: in function 'cmd'
	...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:115: in function 'jump'
	...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:36: in function <...hare/nvim/lazy/snacks.nvim/lua/snacks/picker/actions.lua:35>

[vandalt]

@kamransoomro84 I think this issue is different from the failing health checks.

It occurs when the notebook has no kernelspec attribute in the metadata. I don't think there is an open issue for this at the moment, but it is similar to #17 (which has been fixed by #19). It may be worth creating a separate issue to track this.