VueJS 2.x is deprecated and unmaintained

[aureq]

Prerequisites

• I have searched open and closed issues to make sure that the bug has not yet been reported.

Bug report

Describe the bug
It appears https://github.com/simple-login/app/blob/master/static/package.json references VueJS 2.6.14 but version 2.x has been deprecated and unmaintained for a while according to https://v2.vuejs.org/eol/

Expected behavior
Ideally, running VueJS 3.x would be great, though this will likely require some work. If not possible, it would be great to run on 2.7.16.

Additional context
I'm raising this issue has the EOL message has come up during my self-hosted setup. It may be useful for the SaaS offering too.