Update and remove unused dependencies

package.json

@@ -11,17 +11,15 @@
 		"dev": "gulp watch"
 	},
 	"devDependencies": {
-		"autoprefixer": "^9.8.6",
+		"autoprefixer": "^10.2.4",
 		"browserslist": "^4.14.4",
-		"cross-env": "^7.0.2",
 		"cssnano": "^4.1.10",
 		"gulp": "^4.0.2",
-		"gulp-postcss": "^8.0.0",
+		"gulp-postcss": "^9.0.0",
 		"gulp-pug": "^4.0.1",
 		"gulp-sass": "^4.1.0",
 		"gulp-terser": "^1.4.0",
-		"npm-run-all": "^4.1.5",
+		"postcss": "^8.2.4",
-		"postcss": "^7.0.34",
 		"pug": "^3.0.0",
 		"sass": "^1.26.11"
 	}