cemu: update discord-rpc dependency

discord-rpc has been unmaintained for years. cemu has replaced it with a
new discord rpc implementation but has not cut a new release since 2.6
causing the package to not build when nixpkgs cmake bumped to version 4

pkgs/by-name/ce/cemu/package.nix

@@ -7,6 +7,7 @@
   cubeb,
   curl,
   fetchFromGitHub,
+  fetchpatch2,
   fmt_9,
   gamemode,
   glm,
@@ -66,6 +67,10 @@ stdenv.mkDerivation (finalAttrs: {
     # > SPIRV-Tools-opt
     ./0000-spirv-tools-opt-cmakelists.patch
     ./0002-cemu-imgui.patch
+    (fetchpatch2 {
+      url = "https://github.com/cemu-project/Cemu/commit/c1c2962b6633017cd956c6925288e2529c532ee4.diff?full_index=1";
+      sha256 = "sha256-Dz7WnCf5+Vbr/ETX71wIo/x/zPWdrsOtPH7bsL5Bd+A=";
+    })
   ];
 
   nativeBuildInputs = [