sdl3-ttf: enable plutosvg integration (#419684)

pkgs/by-name/sd/sdl3-ttf/package.nix

···
   harfbuzz,
   glib,
   ninja,
+  plutosvg,
   fixDarwinDylibNames,
 }:
 
···
     freetype
     harfbuzz
     glib
+    plutosvg
   ];
 
   cmakeFlags = [
     (lib.cmakeBool "SDLTTF_STRICT" true)
     (lib.cmakeBool "SDLTTF_HARFBUZZ" true)
-    # disable plutosvg (not in nixpkgs)
-    (lib.cmakeBool "SDLTTF_PLUTOSVG" false)
+    (lib.cmakeBool "SDLTTF_PLUTOSVG" true)
   ];
 
   passthru = {