Fix #429: remove doctests suite and cabal-doctest dependency

source/BNFC.cabal

@@ -3,7 +3,7 @@ Version: 2.9.5
 cabal-version: 2.0
   -- >=1.24 for the custom-setup section
   -- >=2.0  for the build-tools: hspec-discover
-build-type: Custom
+build-type: Simple
 category: Parsing
 Copyright: (c) Andreas Abel, Jonas Almström Duregård, Krasimir Angelov, Jean-Philippe Bernardy, Björn Bringert, Johan Broberg, Kyle Butt, Paul Callaghan, Grégoire Détrez, Markus Forsberg, Ola Frid, Peter Gammie, Thomas Hallgren, Pascal Hof, Simon Huber, Patrik Jansson, Kristofer Johannisson, Antti-Juhani Kaijanaho, Andreas Lööw, Justin Meiners, Kent Mein, Ulf Norell, Gabriele Paganelli, Michael Pellauer, Fabian Ruch, and Aarne Ranta 2002 - 2021. Free software under the BSD 3-clause license.
 License: BSD3
@@ -67,13 +67,6 @@ Source-repository this
   subdir:   source
   tag:      v2.9.5
 
--- Setup using https://github.com/haskellari/cabal-doctest
-custom-setup
- setup-depends:
-   base >= 4 && <5,
-   Cabal >= 2.0 && < 4,
-   cabal-doctest >= 1 && < 1.1
-
 executable bnfc
   default-language:  Haskell2010
   main-is:           Main.hs
@@ -340,18 +333,3 @@ test-suite unit-tests
   autogen-modules:
     -- Generated by cabal
     Paths_BNFC
-
-test-suite doctests
-  default-language:   Haskell2010
-  type:               exitcode-stdio-1.0
-  ghc-options:        -threaded
-  default-extensions: CPP
-  main-is:            doctests.hs
-  build-depends:      base
-    , filepath
-    , BNFC
-      -- The dependency BNFC ensures the build of the library first
-      -- and hence, the presence of Build_doctests.
-      -- See https://hackage.haskell.org/package/cabal-doctest
-    , doctest >= 0.8
-  hs-source-dirs:     test