[fix] LESS sourcemaps broken in less-plugin-clean-css v1.6.0

The ``less-plugin-clean-css`` lacks some maintenance: the sourcemaps are broken
since v1.6.0 (08/2024) [1]

- [1] https://github.com/less/less-plugin-clean-css/issues/42

Closes: https://github.com/searxng/searxng/issues/4143

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/static/themes/simple/gruntfile.js

@@ -119,9 +119,6 @@ module.exports = function (grunt) {
       production: {
         options: {
           paths: ["less"],
-          plugins: [
-            new (require('less-plugin-clean-css'))()
-          ],
           sourceMap: true,
           sourceMapURL: (name) => { const s = name.split('/'); return s[s.length - 1] + '.map'; },
           outputSourceFiles: true,

searx/static/themes/simple/package-lock.json

@@ -25,7 +25,6 @@
         "grunt-xmlmin": "^0.1.8",
         "ionicons": "^7.4.0",
         "less": "^4.2.1",
-        "less-plugin-clean-css": "^1.6.0",
         "sharp": "^0.33.5",
         "stylelint": "^16.12.0",
         "stylelint-config-standard": "^36.0.0",
@@ -5790,19 +5789,6 @@
         "source-map": "~0.6.0"
       }
     },
-    "node_modules/less-plugin-clean-css": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/less-plugin-clean-css/-/less-plugin-clean-css-1.6.0.tgz",
-      "integrity": "sha512-jwXX6WlXT57OVCXa5oBJBaJq1b4s1BOKeEEoAL2UTeEitogQWfTcBbLT/vow9pl0N0MXV8Mb4KyhTGG0YbEKyQ==",
-      "dev": true,
-      "license": "Apache-2.0",
-      "dependencies": {
-        "clean-css": "5.3.3"
-      },
-      "engines": {
-        "node": ">=0.10"
-      }
-    },
     "node_modules/less/node_modules/make-dir": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/make-dir/-/make-dir-2.1.0.tgz",

searx/static/themes/simple/package.json

@@ -14,7 +14,6 @@
     "grunt-xmlmin": "^0.1.8",
     "ionicons": "^7.4.0",
     "less": "^4.2.1",
-    "less-plugin-clean-css": "^1.6.0",
     "sharp": "^0.33.5",
     "stylelint": "^16.12.0",
     "stylelint-config-standard": "^36.0.0",