Docs: Update stylelint (#2564)

* Docs: Update stylelint

Finally figured out how to migrate stylelint to esm

* Try to use later node

.github/workflows/build.yml

@@ -107,7 +107,7 @@ jobs:
     - name: Setup Node
       uses: actions/setup-node@v4
       with:
-        node-version: '16'
+        node-version: '22'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip build tox

gulpfile.babel.js → gulpfile.babel.mjs

@@ -21,7 +21,7 @@ import mqpacker from "css-mqpacker"
 import terser from '@rollup/plugin-terser'
 import {rollup} from "rollup"
 import {babel as rollupBabel, getBabelOutputPlugin} from "@rollup/plugin-babel"
-import stylelint from "gulp-stylelint"
+import gStylelintEsm from 'gulp-stylelint-esm'
 import eslint from "gulp-eslint"
 import rev from "gulp-rev"
 import revReplace from "gulp-rev-replace"
@@ -63,7 +63,7 @@ const config = {
       "./docs/theme/assets/pymdownx-extras/*.js",
       "./docs/theme/assets/pymdownx-extras/*.js.map"
     ],
-    gulp: "gulpfile.babel.js",
+    gulp: "gulpfile.babel.mjs",
     mkdocsSrc: "./docs/src/mkdocs.yml"
   },
   folders: {
@@ -212,7 +212,7 @@ gulp.task("scss:build", gulp.series("scss:build:sass", () => {
 gulp.task("scss:lint", () => {
   return gulp.src(config.files.scss)
     .pipe(
-      stylelint({
+      gStylelintEsm({
         customSyntax: scss,
         reporters: [
           {formatter: "string", console: true}