Revert "Ditch Bash script for custom setup"

This reverts commit 1f1c0d959da699ce04f7951ecbcdb7976c8c0750.

This doesn't work well with multi-component builds. For example, it requires `"haskell.sessionLoading": "singleComponent"` in VSCode, which makes HLS work less reliably.

Setup.hs

@@ -1,14 +0,0 @@
-import Distribution.Simple
-import Distribution.Simple.LocalBuildInfo
-import Distribution.Utils.Path
-import System.Directory
-
-main :: IO ()
-main =
-    defaultMainWithHooks
-        simpleUserHooks
-            -- Place library in the location from which Cabal can bundle it.
-            { buildHook = \pkg lbi hooks flags -> do
-                copyFile "rust/target/debug/libgarnet_rs.a" $ getSymbolicPath (buildDir lbi) </> "libgarnet_rs.a"
-                buildHook simpleUserHooks pkg lbi hooks flags
-            }

garnet.cabal

@@ -6,13 +6,6 @@ author: Patrick Aldis
 maintainer:
     george.thomas@obsidian.systems
     patrick.aldis@obsidian.systems
-build-type: Custom
-
-custom-setup
-    setup-depends:
-        base,
-        Cabal,
-        directory,
 
 common common
     default-language: GHC2024

generate-bindings

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Place library in the location from which Cabal can bundle it.
+cp rust/target/debug/libgarnet_rs.a $(cabal list-bin . | sed -e 's=x/garnet/build/garnet/garnet=build=g')