[ruby-core:125882] [Ruby Feature#22135] Remove deprecated `ObjectSpace#_id2ref`

Issue #22135 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Feature #22135: Remove deprecated `ObjectSpace#_id2ref` https://bugs.ruby-lang.org/issues/22135 * Author: nobu (Nobuyoshi Nakada) * Status: Open ---------------------------------------- As a result of [Feature #15408], the `ObjectSpace#_id2ref` method has been deprecated and now triggers a warning. However, we recognize that its use had already been discouraged for a long time prior to this, and we believe it is rarely used nowadays. Are there any objections to removing this method in version 4.1? [GH-17577](https://github.com/ruby/ruby/pull/17577) -- https://bugs.ruby-lang.org/