xearth: build fix with gcc 14, refactor (#388565)

pkgs/by-name/xe/xearth/package.nix

···
 
   src = fetchurl {
     url = "http://xearth.org/${pname}-${version}.tar.gz";
-    sha256 = "bcb1407cc35b3f6dd3606b2c6072273b6a912cbd9ed1ae22fb2d26694541309c";
+    hash = "sha256-vLFAfMNbP23TYGssYHInO2qRLL2e0a4i+y0maUVBMJw=";
   };
+
+  postPatch = "sed -i '48i #include <stdlib.h>' gifout.c";
 
   nativeBuildInputs = [
     imake
     gccmakedep
   ];
+
   buildInputs = [
     libXt
     libXext
···
     "BINDIR=bin"
     "MANDIR=man/man1"
   ];
+
   installTargets = [
     "install"
     "install.man"
   ];
 
-  meta = with lib; {
+  meta = {
     description = "sets the X root window to an image of the Earth";
     mainProgram = "xearth";
     homepage = "https://xearth.org";
···
       correctly shaded for the current position of the Sun.
       By default, xearth updates the displayed image every  five  minutes.
     '';
-    maintainers = [ maintainers.mafo ];
+    maintainers = with lib.maintainers; [ mafo ];
     license = {
       fullName = "xearth license";
       url = "https://xearth.org/copyright.html";
       free = true;
     };
-    platforms = platforms.unix;
+    platforms = lib.platforms.unix;
   };
-
 }