netbird: move icon to spec-compliant location, remove absolute Exec path

pkgs/by-name/ne/netbird/package.nix

@@ -127,11 +127,11 @@ buildGoModule (finalAttrs: {
         ''
     # assemble & adjust netbird.desktop files for the GUI
     + lib.optionalString (stdenv.hostPlatform.isLinux && componentName == "ui") ''
-      install -Dm644 "$src/client/ui/assets/netbird-systemtray-connected.png" "$out/share/pixmaps/netbird.png"
+      install -Dm644 "$src/client/ui/assets/netbird-systemtray-connected.png" "$out/share/icons/hicolor/256x256/apps/netbird.png"
       install -Dm644 "$src/client/ui/build/netbird.desktop" "$out/share/applications/netbird.desktop"
 
       substituteInPlace $out/share/applications/netbird.desktop \
-        --replace-fail "Exec=/usr/bin/netbird-ui" "Exec=$out/bin/${component.binaryName}"
+        --replace-fail "Exec=/usr/bin/netbird-ui" "Exec=${component.binaryName}"
     '';
 
   nativeInstallCheckInputs = lib.lists.optionals (component ? versionCheckProgramArg) [