utils/gems: don't allow Sorbet to install on Sonoma's system Ruby

[Bo98]

As it is not supported and will error otherwise.

[MikeMcQuaid]

Thanks @Bo98, makes sense!

[buildpulse]

Known disruptive tests have failed for this pull request.

Commit SHA: 1a481be
Build URL: https://github.com/Homebrew/brew/actions/runs/6186785402/attempts/1

Suite Name	Test Name	Details
rspec	SystemCommand with both STDOUT and STDERR output from upstream with default options its result stderr is expected to eq "2\n4\n6\n"	→

[buildpulse]

Known disruptive tests have failed for this pull request.

Commit SHA: 1a481be
Build URL: https://github.com/Homebrew/brew/actions/runs/6186785402/attempts/1

Suite Name	Test Name	Details
rspec	SystemCommand with both STDOUT and STDERR output from upstream with print_stdout echoes both STDOUT and STDERR	→

[Bo98]

Known disruptive tests

Yes it's known for months/years, but super low priority as rspec-retry fixes it.

Not sure why BuildPulse has decided to pick on this pull request randomly, even when it admits it's already "known".

[MikeMcQuaid]

Known disruptive tests

Yes it's known for months/years, but super low priority as rspec-retry fixes it.

Not sure why BuildPulse has decided to pick on this pull request randomly, even when it admits it's already "known".

I think this is just a new feature (that we probably want to disable).