treewide: use scons setup hook

Lots of packages can use it. Here is the list:

- jackmix
- klick
- mixx
- nova-filters
- rhvoice
- giv
- mypaint
- swift-im
- bombono
- mapnik
- serf
- nuitka
- pyexiv2
- godot
- hammer
- toluapp
- btanks
- dxx-rebirth
- endless-sky
- globulation
- the-powder-toy
- fceux
- gpsd
- mongodb
- rippled
- mariadb
- lprof

pkgs/games/endless-sky/default.nix

@@ -22,18 +22,12 @@ stdenv.mkDerivation rec {
     SDL2 libpng libjpeg glew openal scons libmad
   ];
 
+  prefixKey = "PREFIX=";
+
   patches = [
     ./fixes.patch
   ];
 
-  buildPhase = ''
-    scons -j$NIX_BUILD_CORES PREFIX="$out"
-  '';
-
-  installPhase = ''
-    scons -j$NIX_BUILD_CORES install PREFIX="$out"
-  '';
-
   meta = with stdenv.lib; {
     description = "A sandbox-style space exploration game similar to Elite, Escape Velocity, or Star Control";
     homepage = https://endless-sky.github.io/;