Revert "gcc: gcc_13 → gcc_14"

[alyssais]

Description of changes

This reverts commit e9cdb22.

We've encountered multiple GCC 14 internal compiler errors on aarch64. If we wanted to keep it as the default compiler, we'd either have to track the 14.x release branch, or backport about half of it. One Bugzilla thread mentions six patches that should be backported. This doesn't feel good to have as the default compiler. Let's stick with 13 for now until 14.3 is released, hopefully with all the fixes.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[philiptaron]

Thanks @alyssais. This is the right call given the evidence.

Original PR:

• gcc: gcc_13 → gcc_14 #340612