chore: Upgrade CocoaPods to 1.16.2

[mrousavy]

Summary

• Upgrade CocoaPods from 1.15.2 to 1.16.2.
• Upgrade xcodeproj from 1.25.1 to 1.27.0, matching CocoaPods 1.16.2's minimum.
• Upgrade the Ruby toolchain used by iOS CI to Ruby 4.0.5 and lock ActiveSupport to the patched 7.2.3.1 line.
• Add explicit nkf/tsort Ruby stdlib gems required by the newer Ruby/CocoaPods stack.
• Refresh example/ios/Podfile.lock with CocoaPods 1.16.2.

Notes

• CocoaPods 1.16.2 is primarily a bugfix release that bumps the minimum xcodeproj to 1.27.0 to include the revert of breaking Xcode build-setting changes.
• xcodeproj 1.27.0 itself reverts the problematic default build settings introduced in 1.26.0.
• ActiveSupport 7.2.3.1 is the first compatible line in this branch that cleared the OSV advisories found in 7.1.6.

Validation

• PATH="/opt/homebrew/opt/ruby/bin:$PATH" bundle update activesupport
• PATH="/opt/homebrew/opt/ruby/bin:$PATH" bundle exec pod --version
• PATH="/opt/homebrew/opt/ruby/bin:$PATH" bundle exec pod install
• OSV check over all 46 RubyGems in example/Gemfile.lock: 0 vulnerable gems
• ruby -e 'require "yaml"; ARGV.each { |f| YAML.load_file(f); puts "ok #{f}" }' .github/workflows/build-ios.yml .github/workflows/harness-ios.yml .github/workflows/build-ios-release.yml .github/workflows/update-lockfiles.yml
• git diff --check

[mrousavy]

Superseded by #1063, which folds the package upgrades into one PR.