Update actions/checkout action to v4

package.json

@@ -16,21 +16,21 @@
   },
   "devDependencies": {
     "autoprefixer": "10.4.16",
-    "cssnano": "6.0.3",
+    "cssnano": "6.0.2",
     "del": "6.1.1",
     "gulp": "4.0.2",
     "gulp-concat": "2.6.1",
     "gulp-flatmap": "1.0.2",
     "gulp-header": "2.0.9",
     "gulp-optimize-js": "1.1.0",
-    "gulp-postcss": "9.1.0",
+    "gulp-postcss": "9.0.1",
     "gulp-rename": "2.0.0",
     "gulp-sass": "5.1.0",
     "gulp-terser": "2.1.0",
     "lazypipe": "1.0.2",
     "node-sass-tilde-importer": "^1.0.2",
     "postcss": "^8.4.32",
-    "sass": "^1.69.7"
+    "sass": "^1.69.5"
   },
   "dependencies": {
     "@fortawesome/fontawesome-free": "^5.15.4",