data/fonts: cleanup

* make font derivations fixed-output where applicable
 * fix dead links
 * `stdenv.lib` -> `lib` where `stdenv` is not involved
 * remove `meta.platforms = [ unix ]` and `meta.platforms = [ linux ]` because the restriction has no sense for data packages

pkgs/data/fonts/clearlyU/default.nix

@@ -7,18 +7,17 @@ stdenv.mkDerivation {
     url = https://www.math.nmsu.edu/~mleisher/Software/cu/cu12-1.9.tgz;
     sha256 = "1xn14jbv3m1khy7ydvad9ydkn7yygdbhjy9wm1v000jzjwr3lv21";
   };
-  
+
   nativeBuildInputs = [ mkfontdir mkfontscale ];
 
-  installPhase =
-    ''
-      mkdir -p $out/share/fonts
-      cp *.bdf $out/share/fonts
-      cd $out/share/fonts
-      mkfontdir 
-      mkfontscale
-    '';
-  
+  installPhase = ''
+    mkdir -p $out/share/fonts
+    cp *.bdf $out/share/fonts
+    cd $out/share/fonts
+    mkfontdir
+    mkfontscale
+  '';
+
   outputHashAlgo = "sha256";
   outputHashMode = "recursive";
   outputHash = "127zrg65s90ksj99kr9hxny40rbxvpai62mf5nqk853hcd1bzpr6";
@@ -26,6 +25,5 @@ stdenv.mkDerivation {
   meta = {
     description = "A Unicode font";
     maintainers = [stdenv.lib.maintainers.raskin];
-    platforms = stdenv.lib.platforms.unix;
   };
 }