Motivation for this change

https://github.com/CocoaPods/CocoaPods/releases/tag/1.9.2

There's literally nothing in the release notes for this. From inspecting the diff it appears this release exists solely to blacklist activesupport 4.2.11.12. Let's update anyway just to avoid users wondering why we don't have the latest version.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.