website: Remove the v20 working status page

This page is very out-of-date for the current gem5 release (v21.2).
It is confusing to remain part of the gem5 website. It should be
resurrected and updated with the correct information at a later date.

Change-Id: I8f6c9c20cc5a06fda25f1afe327fb6e9e06ae3e3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/55687
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
2 files changed