lxpanel: fix build with gcc14

- add patch from upstream commit:
https://github.com/lxde/lxpanel/commit/0853b0fc981285ebd2ac52f8dfc2a09b1090748c
fixing `incompatible-pointer-types` error with gcc14

pkgs/desktops/lxde/core/lxpanel/default.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchurl,
+  fetchpatch2,
   pkg-config,
   gettext,
   m4,
@@ -38,6 +39,15 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-HjGPV9fja2HCOlBNA9JDDHja0ULBgERRBh8bPqVEHug=";
   };
 
+  patches = [
+    # fix build with gcc14
+    # https://github.com/lxde/lxpanel/commit/0853b0fc981285ebd2ac52f8dfc2a09b1090748c
+    (fetchpatch2 {
+      url = "https://github.com/lxde/lxpanel/commit/0853b0fc981285ebd2ac52f8dfc2a09b1090748c.patch?full_index=1";
+      hash = "sha256-lj4CWdiUQhEc9J8UNKcP7/tmsGnPjA5pwXAok5YFW4M=";
+    })
+  ];
+
   nativeBuildInputs = [
     pkg-config
     gettext