feat(nix): override at-spi2-core postInstall script

- Added a `postInstall` modification to adjust the Xwayland session script in `at-spi2-core`.
- Ensures proper replacement of `xprop` with the path to the package's binary.

overlays/mods/default.nix

@@ -5,4 +5,10 @@ final: prev: {
       ./gnome-console-Add-image-and-file-path-pasting-support-for.patch
     ];
   });
+        at-spi2-core = prev.at-spi2-core.overrideAttrs (oldAttrs: {
+          postInstall = (oldAttrs.postInstall or "") + ''
+            substituteInPlace $out/etc/xdg/Xwayland-session.d/00-at-spi \
+              --replace-fail 'exec xprop' 'exec ${final.xorg.xprop}/bin/xprop'
+          '';
+        });
 }