release: Make fetch happen in GCE images

[cperciva]

Summary

We want to fetch distfiles, regardless of whether they contain known
vulnerabilities or we're building images for a different version of
FreeBSD.

MFC after: 3 days

[emaste]

DISABLE_VULNERABILITIES should really have been something like DISABLE_VULNERABILITY_CHECKS, yeah?

[ivy]

i don't know enough about ports to say if this is the right way to do this, but in principle disabling vulnerability checks here seems correct, otherwise building release would randomly break whenever VuXML is updated. which is, i suppose, what prompted this change in the first place.

[jrtc27]

You were exactly a month late for October 3rd... :)

[cperciva]

In D53569#1222916, @emaste wrote:

DISABLE_VULNERABILITIES should really have been something like DISABLE_VULNERABILITY_CHECKS, yeah?

It's a silly name, but that's what marcus@ picked in February 2004... I had only been a committer for a couple weeks at that point IIRC. :-/