The default Go version bump was accidental

[Benny Siegert <bsiegert%gmail.com@localhost>]

Hi!

From PR pkg/57283, I noticed that the default version of Go in pkgsrc
is currently 120. This was an accidental change. There are a couple
packages (including syncthing) that currently do not work well with Go
1.20, so I had intended to wait until after the branch to flip.

Question to PMC: Should I revert this line back to go119 as the
default, given that we are in a freeze?

-- 
Benny