vifm: JupyterStart always uses sessionfile

Make JupyterStart always use the buffer sessionfile (or create the
default one if none exists) instead of only on first run.

nvim/.config/nvim/after/ftplugin/quarto.lua

@@ -41,7 +41,7 @@ local startsession = function(file, args)
 	})
 end
 vim.api.nvim_create_user_command("JupyterStart", function()
-	startsession()
+	startsession(vim.b["sessionfile"] or default_buffer_session())
 end, {})
 
 vim.api.nvim_create_autocmd({"InsertEnter", "BufEnter"}, {