Only check -Wunused-package by project

Author: philderbeast

Cabal-syntax/Cabal-syntax.cabal

@@ -59,11 +59,6 @@ library
   if impl(ghc >= 8.0) && impl(ghc < 8.8)
     ghc-options: -Wnoncanonical-monadfail-instances
 
-  -- Warning: even though introduced with GHC 8.10, -Wunused-packages gives
-  -- false positives with GHC 8.10.
-  if impl(ghc >= 9)
-    ghc-options: -Wunused-packages
-
   build-tool-depends: alex:alex
 
   exposed-modules:

Cabal/Cabal.cabal

@@ -65,11 +65,6 @@ library
   if impl(ghc >= 8.0) && impl(ghc < 8.8)
     ghc-options: -Wnoncanonical-monadfail-instances
 
-  -- Warning: even though introduced with GHC 8.10, -Wunused-packages gives
-  -- false positives with GHC 8.10.
-  if impl(ghc >= 9)
-    ghc-options: -Wunused-packages
-
   exposed-modules:
     Distribution.Backpack.Configure
     Distribution.Backpack.ComponentsGraph

cabal-install-solver/cabal-install-solver.cabal

@@ -43,11 +43,6 @@ library
   if impl(ghc < 8.8)
     ghc-options: -Wnoncanonical-monadfail-instances
 
-  -- Warning: even though introduced with GHC 8.10, -Wunused-packages gives
-  -- false positives with GHC 8.10.
-  if impl(ghc >= 9)
-    ghc-options: -Wunused-packages
-
   exposed-modules:
     Distribution.Client.Utils.Assertion
 

cabal-install/cabal-install.cabal

@@ -51,11 +51,6 @@ common warnings
     if impl(ghc < 8.8)
       ghc-options: -Wnoncanonical-monadfail-instances
 
-    -- Warning: even though introduced with GHC 8.10, -Wunused-packages gives
-    -- false positives with GHC 8.10.
-    if impl(ghc >= 9)
-      ghc-options: -Wunused-packages
-
 common base-dep
     build-depends: base >=4.10 && <4.20