Remove deprecated Windows 2016 Docker image (O/S no longer in support)

[karianna]

Checklist

• commit message has one of the standard prefixes
• faq.md updated if appropriate
• other documentation is changed or added (if applicable)
• playbook changes run through VPC or QPC (if you have access)
• for inventory.yml changes, bastillion/nagios/jenkins updated accordingly

[Willsparker]

We may as well remove the Win2016 Vagrantfile entirely - It's not part of VPC, and I assume there's no scope to add it to VPC, if it's out of support :-)

[karianna]

We may as well remove the Win2016 Vagrantfile entirely - It's not part of VPC, and I assume there's no scope to add it to VPC, if it's out of support :-)

Shall I remove the 2012 as well in that case?

[Willsparker]

We use 2012 for VPC :)

[karianna]

We use 2012 for VPC :)

Updated, I think I caught all of the references

[karianna]

It does beg the question of whether we should add 2019/2022 instead.

[Willsparker]

I certainly wouldn't be opposed to adding a newer one, however we'd still be blocked by #2178 . Maybe worth opening an issue as a future enhancement, after we've resolved that

[Willsparker]

LGTM

[sxa]

@karianna Would be good to have 2019 since you have requested to use that for JDK19 #2490

I've resolved the merge conflicts in this so I'm going to merge it once the checks pass since it's been sitting for a while :-)