Fix Ambiguous module name Distribution.PackageDescription

Using Stack 2.9.1 to build a package with a dependency on `Cabal` and `process` and:

~~~yaml
resolver: lts-19.25 # GHC 9.0.2 (comes with Cabal-3.4.1.0)
extra-deps:
- Cabal-3.8.1.0
- Cabal-syntax-3.8.1.0
- process-1.6.15.0
~~~

yields error:

~~~
process                      > configure
process                      > [1 of 2] Compiling Main             ( C:\Users\mikep\AppData\Local\Temp\stack-d0efe7ccadb373e9\process-1.6.15.0\Setup.hs, C:\Users\mikep\AppData\Local\Temp\stack-d0efe7ccadb373e9\process-1.6.15.0\.stack-work\dist\d53b6a14\setup\Main.o )
process                      > [2 of 2] Compiling StackSetupShim   ( C:\sr\setup-exe-src\setup-shim-Z6RU0evB.hs, C:\Users\mikep\AppData\Local\Temp\stack-d0efe7ccadb373e9\process-1.6.15.0\.stack-work\dist\d53b6a14\setup\StackSetupShim.o )
process                      >
process                      > C:\sr\setup-exe-src\setup-shim-Z6RU0evB.hs:3:1: error:
process                      >     Ambiguous module name ‘Distribution.PackageDescription’:
process                      >       it was found in multiple packages:
process                      >       Cabal-3.4.1.0 Cabal-syntax-3.8.1.0
process                      >   |
process                      > 3 | import Distribution.PackageDescription (PackageDescription, emptyHookedBuildInfo)
process                      >   |
~~~

This is because `StackSetupShim` is compiled with (a) the version of `Cabal` that comes with GHC 9.0.2 and (b) the package database that includes `Cabal-syntax-3.8.1.0`, and both export
modules named `Distribution.PackageDescription`.

This pull request fixes that problem by specifying that the import of `Distribution.PackageDescription` is to come from the `Cabal` package.

Author: mpilgrem

src/setup-shim/StackSetupShim.hs

@@ -1,6 +1,7 @@
+{-# LANGUAGE PackageImports #-}
 module StackSetupShim where
 import Main
-import Distribution.PackageDescription (PackageDescription, emptyHookedBuildInfo)
+import "Cabal" Distribution.PackageDescription (PackageDescription, emptyHookedBuildInfo)
 import Distribution.Simple
 import Distribution.Simple.Build
 import Distribution.Simple.Setup (ReplFlags, fromFlag, replDistPref, replVerbosity)