Removing old Go versions

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

Hi!

We have a lot of Go versions in the pkgsrc tree. I would like to remove 
some before the next branch (or after?).

go124 is the current version. go123 is still supported.

To build go124 from source, the chain is
go14 - go118 - go120 - go122 - go124

So it looks like go119 and go121 can go.

Any objections?

--
Benny