Kde: fix qt wayland

roles/kde/plasma.nix

@@ -37,6 +37,34 @@ in {
   # Enable the Plasma 6 Desktop Environment
   services.desktopManager.plasma6.enable = true;
 
+  # Same as https://github.com/NixOS/nixpkgs/pull/386932
+  nixpkgs.overlays = [
+    (
+      final: prev: {
+        kdePackages = prev.kdePackages.overrideScope (
+          kFinal: kPrev: {
+            qtbase-vulkan = kPrev.qtbase.overrideAttrs {
+              postFixup = ''
+                moveToOutput      "mkspecs/modules" "$dev"
+                fixQtModulePaths  "$dev/mkspecs/modules"
+                fixQtBuiltinPaths "$out" '*.pr?'
+                patchelf --add-rpath "${final.libmysqlclient}/lib/mariadb" $out/lib/qt-6/plugins/sqldrivers/libqsqlmysql.so
+                patchelf --add-rpath "${final.vulkan-loader}/lib" --add-needed "libvulkan.so" $out/lib/libQt6Gui.so
+              '';
+            };
+          }
+        );
+      }
+    )
+  ];
+
+  system.replaceDependencies.replacements = with pkgs.kdePackages; [
+    {
+      oldDependency = qtbase;
+      newDependency = qtbase-vulkan;
+    }
+  ];
+
   qt.enable = true;
 
   # GTK apps need dconf to grab the correct theme on Wayland