FR: Indicate if `:MasonToolsUpdate` does nothing due to no update available

[chrisgrieser]

Minor QoL thing: When you run :MasonToolsUpdate and there is no update available, there is no indication or response to the user. It would be a better UX if you'd get a short notification "no update available" to inform the user. (ensuring that, for instance, you haven't mistyped the command or your keymap for it)

[nvs]

You could probably do something like this, given that it seems event.data should be empty when nothing is done.

vim.api.nvim_create_autocmd('User', {
	pattern = 'MasonToolsUpdateCompleted',
	callback = function(event)
		vim.schedule(function()
			if #event.data == 0 then
				print('no changes')
			else
				print('finished')
			end
		end)
	end,
})