Cardano Updates

The `withGHCTooling` block in dynamic.nix sourced `happy` and `alex`
from nixpkgs's `pkgs.haskellPackages`, which builds them with a
different GHC than the shell's `compiler` (currently ghc-9.10.3 in
nixpkgs vs ghc-9.8.4 in our shell). The Haskell library outputs of
both packages live under `lib/ghc-<other-ver>/lib/*.dylib`; their
.dylib path strings anchor the foreign GHC in the closure via Nix's
reference scanner.

On aarch64-darwin this dragged in ghc-9.10.3 (1.40 GB) and
ghc-9.10.3-doc (753 MB) — ~2.15 GB of essentially-unused payload.

Switch to haskell.nix's `tool` builder (same pattern as cross-js.nix
and cross-windows.nix), which builds happy/alex with the shell's
`compiler-nix-name`. The resulting library outputs reference the GHC
that's already in the closure rather than dragging in a second one.

While here:
* swap `git` → `gitMinimal` — drops the heavyweight perl-modules and
  git-doc that aren't useful inside the dev shell (~150 MB cascade).
* tool-map.nix: drop `inherit cabalProjectLocal` from happy/alex.
  They're standard mainline packages and build cleanly from regular
  hackage; the inherited cabalProjectLocal pinned a head.hackage SHA
  that was stale and broke fresh evaluations of `(tool "happy")` /
  `(tool "alex")`. While there, bump happy 1.20.1.1 → 2.1.7 and
  alex 3.2.7.3 → 3.5.4.0 to match what nixpkgs.haskellPackages was
  shipping previously, so users see no behavioural change.

Measured on aarch64-darwin (ghc98-minimal-ghc):
  before:  6.12 GB / 228 paths
  after :  4.00 GB / 196 paths
  saved :  2.12 GB (34.7% smaller)

Top removed paths:
  ghc-9.10.3              1399 MB
  ghc-9.10.3-doc           753 MB
  git-2.51.2                49 MB
  git-2.51.2-doc            15 MB
  perl5.40.0-SSLeay/Mozilla/IO-Socket-SSL (gitMinimal cascade)

Verified inside the patched shell:
  $ ghc --version    # 9.8.4
  $ cabal --version  # 3.17.0.0
  $ happy --version  # 2.1.7 (same as before)
  $ alex --version   # 3.5.4.0 (same as before)
  $ git --version    # 2.51.2