Cardano Updates

The GHC RTS references dlopen/dlclose/dlsym/dlerror even with
-dynamic-system-linker disabled. Add -ldl to the android
iserv-proxy-interpreter linker flags to resolve undefined symbols.

Also update the head.hackage repository hash in test/cabal.project.local.

- Add ghc-9.12.4-iog branch on stable-haskell/ghc from release tag
- Add lazy-inputs/ghc9124 flake input
- Add ghc9124 compiler definition in bootstrap.nix
- Update latestVerMap to default 9.12 series to 9.12.4
- Add ghc9124 to ghc9141 bootstrap fallback chain
- Create ghc-9.12.4-Cabal-3.14.patch (adapted for 9.12.4 changes
  in utils/genprimopcode/Main.hs)
- Exclude ghc-16bit-elf-section-header-overflow.patch from 9.12.4+
  (already upstreamed)

* Extract ghc-options from plan.json configure-args automatically

ghc-options set in cabal.project files (via package or program-options
stanzas) were previously ignored by haskell.nix, requiring users to
duplicate them in modules. Now that nix-tools includes configure-args
in plan.json (#2484), parse them and apply --ghc-option/--ghcjs-option
entries as package-level ghcOptions automatically.

* Pass other options through too.

nixpkgs 26.05 removed 'pie' from the hardening system entirely -- PIE
is now enabled by default in compilers. Any mention of 'pie' in either
hardeningEnable or hardeningDisable triggers a deprecation warning:

  "The 'pie' hardening flag has been removed in favor of enabling PIE
   by default in compilers and should no longer be used."

This causes ~68 warnings per evaluation for projects with musl
cross-compilation, which is every haskell.nix project using
crossPlatforms with musl64 or aarch64-multiplatform-musl.

Remove the two places where 'pie' was added to hardeningDisable:
- builder/comp-builder.nix: every Haskell component on musl
- compiler/ghc/default.nix: GHC itself on musl targets