Remove Kernel#trust, #unstrust and #untrusted?

[AI-Mozi]

#1016
Feature #16131

The following deprecated methods are removed.
[ ] Kernel#trust, Kernel#untrust, Kernel#untrusted?
[Feature #16131]

Idk if this is the correct way to write removed specs and also I had a problem with untrusted? error message. It won't mach with "undefined method `untrusted?' for".

[headius]

The policy in the past has been to avoid writing specs for things that just aren't there, because obviously there's an infinite number of things that aren't there. I don't know what policy we want to have going forward. Everyone's excited about removing these methods but I don't know if we need to test for that condition.

[AI-Mozi]

It makes sense, I'll just close this pr then, thanks.

[andrykonchin]

The only change (for all the removed methods) that might be appropriate is to fix version guards for deprecation warnings and replace ""..."3.0" with ""..."3.2" as far as only in Ruby 3.2 behaviour changed and warnings were still printed in Ruby 3.1.

Just for the record, the commit removing the methods is ruby/ruby@39bc5de

[eregon]

I think it could be worthwhile to test this (with respond_to?), otherwise other Ruby implementations might keep these methods longer than they should.
OTOH there is already one way that should lead to remove these methods: the NEWS of 3.2 mention this removal (e.g. oracle/truffleruby#3039).
So indeed it seem unnecessary.

(there is also https://github.com/oracle/truffleruby/blob/master/spec/truffle/methods_spec.rb but that's currently truffleruby-specific)

[eregon]

FYI the specs with respond_to? were added in #1031, I think it makes sense and it's natural to add such specs when following the NEWS file from 3.2.