[bug] Random exception updating extmark

[Ajaymamtora]

Can the buffer id be checked before updating?

Error executing vim.schedule lua callback: ...are/nvim/lazy/nvim-lightbulb/lua/nvim-lightbulb/init.lua:170: scoped variable: Invalid buffer id: 218
stack traceback:
	[C]: in function '__index'
	...are/nvim/lazy/nvim-lightbulb/lua/nvim-lightbulb/init.lua:170: in function 'update_extmark'
	...are/nvim/lazy/nvim-lightbulb/lua/nvim-lightbulb/init.lua:265: in function 'handler'
	.../bob/download/v0.10.2/share/nvim/runtime/lua/vim/lsp.lua:936: in function 'handler'
	...wnload/v0.10.2/share/nvim/runtime/lua/vim/lsp/client.lua:687: in function ''
	vim/_editor.lua: in function <vim/_editor.lua:0>