Fix grammar

neither…nor, completing what done in haskell#9162

Author: ffaf1

Cabal/src/Distribution/PackageDescription/Check/Warning.hs

@@ -343,9 +343,9 @@ ppExplanation SignaturesCabal2 =
   "To use the 'signatures' field the package needs to specify "
     ++ "at least 'cabal-version: 2.0'."
 ppExplanation AutogenNotExposed =
-  "An 'autogen-module' is neither on 'exposed-modules' or 'other-modules'."
+  "An 'autogen-module' is neither on 'exposed-modules' nor 'other-modules'."
 ppExplanation AutogenIncludesNotIncluded =
-  "An include in 'autogen-includes' is neither in 'includes' or "
+  "An include in 'autogen-includes' is neither in 'includes' nor "
     ++ "'install-includes'."
 ppExplanation (NoMainIs eName) =
   "No 'main-is' field found for executable " ++ prettyShow eName

cabal-testsuite/PackageTests/Check/ConfiguredPackage/Sanity/AutogenIncludes/cabal.out

@@ -1,4 +1,4 @@
 # cabal check
 The package will not build sanely due to these errors:
-Error: An include in 'autogen-includes' is neither in 'includes' or 'install-includes'.
+Error: An include in 'autogen-includes' is neither in 'includes' nor 'install-includes'.
 Error: Hackage would reject this package.