Revert "use doctests-parallel with ghc-lib dependency instead of ghc"

This reverts commit ac2e6f1.

Author: peterbecich

cabal.project

@@ -77,9 +77,3 @@ package hackage-server
 --
 --   flags: +build-hackage-import
 --   flags: +cabal-parsers
-
-source-repository-package
-  type: git
-  location: https://github.com/peterbecich/doctest-parallel.git
-  tag: daf8475f556af830c73af614d8706a3d5f2e0f22
-  --sha256: 0jy5ffnn6krxkwlir7i7m9knn3xd1j973fy50nlmkzxfdpnzmjay

hackage-server.cabal

@@ -647,5 +647,5 @@ test-suite DocTests
   main-is:        DocTestMain.hs
   build-depends:
     , lib-server
-    , doctest-parallel >= 0.2.0
+    , doctest-parallel >= 0.3.0
         -- doctest-parallel-0.2.2 is the first to filter out autogen-modules