haskellPackages.haskell-language-server: 0.2.0 -> 0.3.0

While we are at it I:
* Disable tests, because I can‘t keep up with the speed hls introduces
more tests that cause trouble in nixpkgs.
* Fix builds of fourmolu and retrie
* Remove the wrapper for hls which is obsolete because of improved
package detection in hie-bios. And added a note that this can be removed
for ghcide soon, too.

pkgs/development/haskell-modules/with-packages-wrapper.nix

@@ -105,8 +105,9 @@ symlinkJoin {
         --set "NIX_${ghcCommandCaps}_LIBDIR" "${libDir}"
     fi
 
-    # ghcide and haskell-language-server do package discovery without calling our ghc wrapper.
-    for prg in ghcide haskell-language-server; do
+    # ghcide 0.2.0 does package discovery without calling our ghc wrapper.
+    # 2020-08-16 We can most likely remove this workaround as soon as we build ghcide with a newer hie-bios (currently we use 0.5.1 from stack)
+    for prg in ghcide; do
       if [[ -x "$out/bin/$prg" ]]; then
         wrapProgram $out/bin/$prg  \
           --set "NIX_${ghcCommandCaps}"        "$out/bin/${ghcCommand}"     \