pg-golang: no longer removes destroot default

[exprez135]

• Previously caused an error if destroot was not included explicitly in PortFile.
• MacPorts will now ordinarily run the default destroot command unless overriden manually with destroot { … }.

Closes: https://trac.macports.org/ticket/72395

Description

As described in Trac: The golang portgroup currently sets the destroot to {}, and also causes an error if the user has not otherwise set the destroot phase.

This seems to assume that packages configured with the portgroup don't have proper Makefiles that should be used with make install DESTDIR=${destroot}. The error messages give guidance in the case that users are just relying on the default golang build.cmd.

I believe that this change would not break any existing port, since any current port using the golang group has to have set the destroot phase. Any new port can then rely on a good makefile (if it exists), or can set their own destroot phase.

@mascguy is assigned to this ticket on Trac.

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 26.0.1 25A362 arm64
Xcode 16.4 16F6

To test, I've used this change in a different branch to test a new port that I'd like to submit to MacPorts once the current destroot behavior has changed: https://github.com/exprez135/macports-ports/tree/add-senpai

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?